Implement code generation

include/cppast/code_generator.hpp

@@ -0,0 +1,421 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#ifndef CPPAST_CODE_GENERATOR_HPP_INCLUDED
+#define CPPAST_CODE_GENERATOR_HPP_INCLUDED
+
+#include <cstring>
+
+#include <type_safe/index.hpp>
+
+#include <cppast/cpp_entity.hpp>
+#include <cppast/cpp_entity_ref.hpp>
+
+namespace cppast
+{
+    /// A simple string view implementation, like [std::string_view]().
+    ///
+    /// It "views" - stores a pointer to - some kind of string.
+    class string_view
+    {
+    public:
+        /// \effects Creates it viewing the [std::string]().
+        string_view(const std::string& str) noexcept : str_(str.c_str()), length_(str.length())
+        {
+        }
+
+        /// \effects Creates it viewing the C string `str`.
+        constexpr string_view(const char* str) noexcept : str_(str), length_(std::strlen(str))
+        {
+        }
+
+        /// \effects Creates it viewing the C string literal.
+        template <std::size_t Size>
+        constexpr string_view(const char (&str)[Size]) noexcept : str_(str), length_(Size - 1u)
+        {
+        }
+
+        /// \returns The number of characters.
+        constexpr std::size_t length() const noexcept
+        {
+            return length_;
+        }
+
+        /// \returns The C string.
+        constexpr const char* c_str() const noexcept
+        {
+            return str_;
+        }
+
+        /// \returns The character at the given index.
+        /// \requires `i < length()`.
+        char operator[](type_safe::index_t i) const noexcept
+        {
+            return type_safe::at(str_, i);
+        }
+
+    private:
+        const char* str_;
+        std::size_t length_;
+    };
+
+    /// \exclude
+    namespace detail
+    {
+        template <typename Tag>
+        class semantic_string_view
+        {
+        public:
+            template <typename T>
+            explicit semantic_string_view(T&& obj,
+                                          decltype(string_view(std::forward<T>(obj)), 0) = 0)
+            : str_(std::forward<T>(obj))
+            {
+            }
+
+            const string_view& str() const noexcept
+            {
+                return str_;
+            }
+
+        private:
+            string_view str_;
+        };
+    } // namespace detail
+
+    /// A special [cppast::string_view]() representing a C++ keyword token.
+    using keyword = detail::semantic_string_view<struct keyword_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ identifier token.
+    using identifier = detail::semantic_string_view<struct identifier_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ string or character literal token.
+    using string_literal = detail::semantic_string_view<struct str_literal_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ integer literal token.
+    using int_literal = detail::semantic_string_view<struct int_literal_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ floating point literal token.
+    using float_literal = detail::semantic_string_view<struct float_literal_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ punctuation token like `.` or `(`.
+    using punctuation = detail::semantic_string_view<struct punctuation_tag>;
+
+    /// A special [cppast::string_view]() representing a C++ preprocessor token.
+    using preprocessor_token = detail::semantic_string_view<struct preprocessor_tag>;
+
+    /// A special [cppast::string_view]() representing a sequence of unknown C++ tokens.
+    using token_seq = detail::semantic_string_view<struct token_seq_tag>;
+
+    /// Tag type to represent an end-of-line character.
+    constexpr struct newl_t
+    {
+        constexpr newl_t() noexcept
+        {
+        }
+    } newl;
+
+    /// Tag type to represent a single space character.
+    constexpr struct whitespace_t
+    {
+        constexpr whitespace_t() noexcept
+        {
+        }
+    } whitespace;
+
+    /// Base class to control the code generation.
+    ///
+    /// Inherit from it to customize how a [cppast::cpp_entity]() is printed
+    /// by [cppast::generate_code]().
+    class code_generator
+    {
+    public:
+        code_generator(const code_generator&) = delete;
+        code_generator& operator=(const code_generator&) = delete;
+        virtual ~code_generator() noexcept               = default;
+
+        /// Sentinel type used to output a given entity.
+        class output
+        {
+        public:
+            /// \effects Creates it giving the generator, the entity
+            /// and whether or not the entity is a container.
+            /// It is a container if while this object lives
+            /// any other `output` objects are created.
+            ///
+            /// It will call `on_container_begin()` or `on_leaf()`,
+            /// respectively.
+            explicit output(type_safe::object_ref<code_generator>   gen,
+                            type_safe::object_ref<const cpp_entity> e, bool is_container)
+            : gen_(gen), print_(is_container ? gen_->on_container_begin(*e) : gen_->on_leaf(*e))
+            {
+                if (is_container)
+                    e_ = e;
+            }
+
+            /// \effects If the entity is a container
+            /// and `on_container_begin()` returned `true`,
+            /// calls `on_container_end()`,
+            /// else does nothing.
+            ~output() noexcept
+            {
+                if (print_ && e_)
+                    gen_->on_container_end(e_.value());
+            }
+
+            output(const output&) = delete;
+            output& operator=(const output&) = delete;
+
+            /// \returns Whether or not the `on_XXX` function returned `true`.
+            /// \notes If this returns `false`,
+            /// the other functions have no effects.
+            explicit operator bool() const noexcept
+            {
+                return print_;
+            }
+
+            /// \returns A reference to the generator.
+            type_safe::object_ref<code_generator> generator() const noexcept
+            {
+                return gen_;
+            }
+
+            /// \effects Call `do_indent()` followed by `do_write_newline()` (if `print_newline` is `true`).
+            void indent(bool print_newline = true) const noexcept
+            {
+                if (print_)
+                {
+                    gen_->do_indent();
+                    if (print_newline)
+                        gen_->do_write_newline();
+                }
+            }
+
+            /// \effects Calls `do_unindent()`.
+            void unindent() const noexcept
+            {
+                if (print_)
+                    gen_->do_unindent();
+            }
+
+            /// \effects Calls `do_write_keyword()`.
+            const output& operator<<(const keyword& k) const
+            {
+                if (print_)
+                    gen_->do_write_keyword(k.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_identifier()`.
+            const output& operator<<(const identifier& ident) const
+            {
+                if (print_)
+                    gen_->do_write_identifier(ident.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_reference()`.
+            template <typename T, class Predicate>
+            const output& operator<<(const basic_cpp_entity_ref<T, Predicate>& ref) const
+            {
+                if (print_)
+                    gen_->do_write_reference(ref.id(), ref.name());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_punctuation()`.
+            const output& operator<<(const punctuation& punct) const
+            {
+                if (print_)
+                    gen_->do_write_punctuation(punct.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_str_literal`.
+            const output& operator<<(const string_literal& lit) const
+            {
+                if (print_)
+                    gen_->do_write_str_literal(lit.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_int_literal()`.
+            const output& operator<<(const int_literal& lit) const
+            {
+                if (print_)
+                    gen_->do_write_int_literal(lit.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_float_literal()`.
+            const output& operator<<(const float_literal& lit) const
+            {
+                if (print_)
+                    gen_->do_write_float_literal(lit.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_preprocessor()`.
+            const output& operator<<(const preprocessor_token& tok) const
+            {
+                if (print_)
+                    gen_->do_write_preprocessor(tok.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_token_seq()`.
+            const output& operator<<(const token_seq& seq) const
+            {
+                if (print_)
+                    gen_->do_write_token_seq(seq.str());
+                return *this;
+            }
+
+            /// \effects Calls `do_write_newline()`.
+            const output& operator<<(newl_t) const
+            {
+                if (print_)
+                    gen_->do_write_newline();
+                return *this;
+            }
+
+            /// \effects Calls `do_write_whitespace()`.
+            const output& operator<<(whitespace_t) const
+            {
+                if (print_)
+                    gen_->do_write_whitespace();
+                return *this;
+            }
+
+        private:
+            type_safe::object_ref<code_generator>     gen_;
+            type_safe::optional_ref<const cpp_entity> e_;
+            bool                                      print_;
+        };
+
+    protected:
+        code_generator() noexcept = default;
+
+    private:
+        /// \effects Will be invoked before code of a container entity is generated.
+        /// The base class version has no effect.
+        /// \returns Whether or not that entity should actually be generated.
+        /// The base class version returns `true`.
+        virtual bool on_container_begin(const cpp_entity& e)
+        {
+            (void)e;
+            return true;
+        }
+
+        /// \effects Will be invoked after all code of a container entity has been generated.
+        /// The base class version has no effect.
+        virtual void on_container_end(const cpp_entity& e)
+        {
+            (void)e;
+        }
+
+        /// \effects Will be invoked before code of a non-container entity is generated.
+        /// The base class version has no effect.
+        /// \returns Whether or not that entity should actually be generated.
+        /// The base class version returns `true`.
+        virtual bool on_leaf(const cpp_entity& e)
+        {
+            (void)e;
+            return true;
+        }
+
+        /// \effects Will be invoked when the indentation level should be increased by one.
+        /// The level change must be applied on the next call to `do_write_newline()`.
+        virtual void do_indent() = 0;
+
+        /// \effects Will be invoked when the indentation level should be decreased by one.
+        /// The level change must be applied immediately if nothing else has been written on the current line.
+        virtual void do_unindent() = 0;
+
+        /// \effects Writes the given token sequence.
+        virtual void do_write_token_seq(string_view tokens) = 0;
+
+        /// \effects Writes the specified special token.
+        /// The base class version simply forwards to `do_write_token_seq()`.
+        /// \notes This is useful for syntax highlighting, for example.
+        /// \group write
+        virtual void do_write_keyword(string_view keyword)
+        {
+            do_write_token_seq(keyword);
+        }
+        /// \group write
+        virtual void do_write_identifier(string_view identifier)
+        {
+            do_write_token_seq(identifier);
+        }
+        /// \group write
+        virtual void do_write_reference(type_safe::array_ref<const cpp_entity_id> id,
+                                        string_view                               name)
+        {
+            (void)id;
+            do_write_token_seq(name);
+        }
+        /// \group write
+        virtual void do_write_punctuation(string_view punct)
+        {
+            do_write_token_seq(punct);
+        }
+        /// \group write
+        virtual void do_write_str_literal(string_view str)
+        {
+            do_write_token_seq(str);
+        }
+        /// \group write
+        virtual void do_write_int_literal(string_view str)
+        {
+            do_write_token_seq(str);
+        }
+        /// \group write
+        virtual void do_write_float_literal(string_view str)
+        {
+            do_write_token_seq(str);
+        }
+        /// \group write
+        virtual void do_write_preprocessor(string_view punct)
+        {
+            do_write_token_seq(punct);
+        }
+
+        /// \effects Writes a newline.
+        /// It is guaranteed that this is the only way a newline will be printed.
+        /// The base class forwards to `do_write_token_seq()`.
+        virtual void do_write_newline()
+        {
+            do_write_token_seq("\n");
+        }
+        /// \effects Writes a whitespace character.
+        /// It will be invoked only where a whitespace is truly needed,
+        /// like between two keywords.
+        /// The base class forwards to `do_write_token_seq()`.
+        virtual void do_write_whitespace()
+        {
+            do_write_token_seq(" ");
+        }
+    };
+
+    /// Generates code for the given entity.
+    ///
+    /// How the code is generated is customized by the generator.
+    /// The implementation will write whitespace only where necessary,
+    /// but a newline after each entity.
+    /// This allows customization of formatting.
+    void generate_code(code_generator& generator, const cpp_entity& e);
+
+    /// \exclude
+    class cpp_template_argument;
+
+    /// \exclude
+    namespace detail
+    {
+        void write_template_arguments(code_generator::output&                           output,
+                                      type_safe::array_ref<const cpp_template_argument> arguments);
+    } // namespace detail
+} // namespace cppast
+
+#endif // CPPAST_CODE_GENERATOR_HPP_INCLUDED

include/cppast/cpp_array_type.hpp

@@ -44,7 +44,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::array;
+            return cpp_type_kind::array_t;
         }
 
         std::unique_ptr<cpp_type>       type_;

include/cppast/cpp_decltype_type.hpp

@@ -33,7 +33,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::decltype_;
+            return cpp_type_kind::decltype_t;
         }
 
         std::unique_ptr<cpp_expression> expr_;
@@ -54,7 +54,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::decltype_auto;
+            return cpp_type_kind::decltype_auto_t;
         }
     };
 } // namespace cppast

include/cppast/cpp_expression.hpp

@@ -14,9 +14,9 @@ namespace cppast
     /// The kind of a [cppast::cpp_expression]().
     enum class cpp_expression_kind
     {
-        literal,
+        literal_t,
 
-        unexposed,
+        unexposed_t,
     };
 
     /// Base class for all C++ expressions.
@@ -83,7 +83,7 @@ namespace cppast
 
         cpp_expression_kind do_get_kind() const noexcept override
         {
-            return cpp_expression_kind::unexposed;
+            return cpp_expression_kind::unexposed_t;
         }
 
         std::string str_;
@@ -115,11 +115,17 @@ namespace cppast
 
         cpp_expression_kind do_get_kind() const noexcept override
         {
-            return cpp_expression_kind::literal;
+            return cpp_expression_kind::literal_t;
         }
 
         std::string value_;
     };
+
+    /// \exclude
+    namespace detail
+    {
+        void write_expression(code_generator::output& output, const cpp_expression& expr);
+    } // namespace detail
 } // namespace cppast
 
 #endif // CPPAST_CPP_EXPRESSION_HPP_INCLUDED

include/cppast/cpp_function_type.hpp

@@ -73,7 +73,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::function;
+            return cpp_type_kind::function_t;
         }
 
         std::unique_ptr<cpp_type>        return_type_;
@@ -154,7 +154,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::member_function;
+            return cpp_type_kind::member_function_t;
         }
 
         std::unique_ptr<cpp_type>        class_type_, return_type_;
@@ -197,7 +197,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::member_object;
+            return cpp_type_kind::member_object_t;
         }
 
         std::unique_ptr<cpp_type> class_type_, object_type_;

include/cppast/cpp_template.hpp

@@ -165,7 +165,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::template_instantiation;
+            return cpp_type_kind::template_instantiation_t;
         }
 
         type_safe::variant<std::vector<cpp_template_argument>, std::string> arguments_;

include/cppast/cpp_template_parameter.hpp

@@ -124,7 +124,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::template_parameter;
+            return cpp_type_kind::template_parameter_t;
         }
 
         cpp_template_type_parameter_ref parameter_;

include/cppast/cpp_type.hpp

@@ -9,34 +9,35 @@
 
 #include <cppast/detail/intrusive_list.hpp>
 #include <cppast/cpp_entity_ref.hpp>
+#include <cppast/code_generator.hpp>
 
 namespace cppast
 {
     /// The kinds of a [cppast::cpp_type]().
     enum class cpp_type_kind
     {
-        builtin,
-        user_defined,
+        builtin_t,
+        user_defined_t,
 
-        auto_,
-        decltype_,
-        decltype_auto,
+        auto_t,
+        decltype_t,
+        decltype_auto_t,
 
-        cv_qualified,
-        pointer,
-        reference,
+        cv_qualified_t,
+        pointer_t,
+        reference_t,
 
-        array,
-        function,
-        member_function,
-        member_object,
+        array_t,
+        function_t,
+        member_function_t,
+        member_object_t,
 
-        template_parameter,
-        template_instantiation,
+        template_parameter_t,
+        template_instantiation_t,
 
-        dependent,
+        dependent_t,
 
-        unexposed,
+        unexposed_t,
     };
 
     /// Base class for all C++ types.
@@ -95,7 +96,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::unexposed;
+            return cpp_type_kind::unexposed_t;
         }
 
         std::string name_;
@@ -163,7 +164,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::builtin;
+            return cpp_type_kind::builtin_t;
         }
 
         cpp_builtin_type_kind kind_;
@@ -207,7 +208,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::user_defined;
+            return cpp_type_kind::user_defined_t;
         }
 
         cpp_type_ref entity_;
@@ -228,7 +229,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::auto_;
+            return cpp_type_kind::auto_t;
         }
     };
 
@@ -269,7 +270,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::dependent;
+            return cpp_type_kind::dependent_t;
         }
 
         std::string               name_;
@@ -331,7 +332,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::cv_qualified;
+            return cpp_type_kind::cv_qualified_t;
         }
 
         std::unique_ptr<cpp_type> type_;
@@ -361,7 +362,7 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::pointer;
+            return cpp_type_kind::pointer_t;
         }
 
         std::unique_ptr<cpp_type> pointee_;
@@ -409,12 +410,31 @@ namespace cppast
 
         cpp_type_kind do_get_kind() const noexcept override
         {
-            return cpp_type_kind::reference;
+            return cpp_type_kind::reference_t;
         }
 
         std::unique_ptr<cpp_type> referee_;
         cpp_reference             ref_;
     };
+
+    /// \exclude
+    namespace detail
+    {
+        // whether or not it requires special treatment when printing it
+        // i.e. function pointer types are complex as the identifier has to be put inside
+        bool is_complex_type(const cpp_type& type) noexcept;
+
+        // write part of the type that comes before the variable name
+        void write_type_prefix(code_generator::output& output, const cpp_type& type);
+
+        // write part of the type that comes after the name
+        // for non-complex types, this does nothing
+        void write_type_suffix(code_generator::output& output, const cpp_type& type);
+
+        // write prefix, variadic, name, suffix
+        void write_type(code_generator::output& output, const cpp_type& type, std::string name,
+                        bool is_variadic = false);
+    } // namespace detail
 } // namespace cppast
 
 #endif // CPPAST_CPP_TYPE_HPP_INCLUDED

src/code_generator.cpp

@@ -0,0 +1,899 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#include <cppast/code_generator.hpp>
+
+#include <cppast/cpp_alias_template.hpp>
+#include <cppast/cpp_class.hpp>
+#include <cppast/cpp_class_template.hpp>
+#include <cppast/cpp_entity_kind.hpp>
+#include <cppast/cpp_enum.hpp>
+#include <cppast/cpp_file.hpp>
+#include <cppast/cpp_function.hpp>
+#include <cppast/cpp_function_template.hpp>
+#include <cppast/cpp_language_linkage.hpp>
+#include <cppast/cpp_member_function.hpp>
+#include <cppast/cpp_member_variable.hpp>
+#include <cppast/cpp_namespace.hpp>
+#include <cppast/cpp_preprocessor.hpp>
+#include <cppast/cpp_template_parameter.hpp>
+#include <cppast/cpp_type_alias.hpp>
+#include <cppast/cpp_variable.hpp>
+#include <cppast/cpp_variable_template.hpp>
+
+using namespace cppast;
+
+namespace
+{
+    template <typename Sep>
+    auto write_sep(code_generator::output& output, Sep s) -> decltype(output << s)
+    {
+        return output << s;
+    }
+
+    template <typename Sep>
+    auto write_sep(code_generator::output& output, Sep s) -> decltype(s(output))
+    {
+        return s(output);
+    }
+
+    template <class Container, typename Sep>
+    bool write_container(code_generator::output& output, const Container& cont, Sep s)
+    {
+        auto need_sep = false;
+        for (auto& child : cont)
+        {
+            if (need_sep)
+                write_sep(output, s);
+            else
+                need_sep = true;
+            generate_code(*output.generator(), child);
+        }
+        return need_sep;
+    }
+
+    void generate_file(code_generator& generator, const cpp_file& f)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(f), true);
+        if (output)
+        {
+            write_container(output, f, newl);
+            output << newl;
+        }
+    }
+
+    void generate_macro_definition(code_generator& generator, const cpp_macro_definition& def)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(def), false);
+        if (output)
+        {
+            output << preprocessor_token("#define") << whitespace << identifier(def.name());
+            if (def.is_function_like())
+                output << preprocessor_token("(") << preprocessor_token(def.parameters().value())
+                       << preprocessor_token(")");
+            if (!def.replacement().empty())
+                output << whitespace << preprocessor_token(def.replacement()) << newl;
+            else
+                output << newl;
+        }
+    }
+
+    void generate_include_directive(code_generator& generator, const cpp_include_directive& include)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(include), false);
+        if (output)
+        {
+            output << preprocessor_token("#include") << whitespace;
+            if (include.include_kind() == cpp_include_kind::system)
+                output << preprocessor_token("<");
+            else
+                output << preprocessor_token("\"");
+            output << include.target();
+            if (include.include_kind() == cpp_include_kind::system)
+                output << preprocessor_token(">");
+            else
+                output << preprocessor_token("\"");
+            output << newl;
+        }
+    }
+
+    void generate_language_linkage(code_generator& generator, const cpp_language_linkage& linkage)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(linkage), true);
+        if (output)
+        {
+            output << keyword("extern") << whitespace << string_literal(linkage.name());
+            if (linkage.is_block())
+            {
+                output << punctuation("{");
+                output.indent();
+
+                write_container(output, linkage, newl);
+
+                output.unindent();
+                output << punctuation("}") << newl;
+            }
+            else
+            {
+                output << whitespace;
+                generate_code(generator, *linkage.begin());
+            }
+        }
+    }
+
+    void generate_namespace(code_generator& generator, const cpp_namespace& ns)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(ns), true);
+        if (output)
+        {
+            if (ns.is_inline())
+                output << keyword("inline") << whitespace;
+            output << keyword("namespace") << whitespace << identifier(ns.name());
+            output << punctuation("{");
+            output.indent();
+
+            write_container(output, ns, newl);
+
+            output.unindent();
+            output << punctuation("}") << newl;
+        }
+    }
+
+    void generate_namespace_alias(code_generator& generator, const cpp_namespace_alias& alias)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
+        if (output)
+            output << keyword("namespace") << whitespace << identifier(alias.name())
+                   << punctuation("=") << alias.target() << punctuation(";") << newl;
+    }
+
+    void generate_using_directive(code_generator& generator, const cpp_using_directive& directive)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(directive), false);
+        if (output)
+            output << keyword("using") << whitespace << keyword("namespace") << whitespace
+                   << directive.target() << punctuation(";") << newl;
+    }
+
+    void generate_using_declaration(code_generator&              generator,
+                                    const cpp_using_declaration& declaration)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(declaration),
+                                      false);
+        if (output)
+            output << keyword("using") << whitespace << declaration.target() << punctuation(";")
+                   << newl;
+    }
+
+    void generate_type_alias(code_generator& generator, const cpp_type_alias& alias)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
+        if (output)
+        {
+            output << keyword("using") << whitespace << identifier(alias.name())
+                   << punctuation("=");
+            detail::write_type(output, alias.underlying_type(), "");
+            output << punctuation(";") << newl;
+        }
+    }
+
+    void generate_enum_value(code_generator& generator, const cpp_enum_value& value)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(value), false);
+        if (output)
+        {
+            output << identifier(value.name());
+            if (value.value())
+            {
+                output << punctuation("=");
+                detail::
+                    write_expression(output,
+                                     value.value()
+                                         .value()); // should have named something differently...
+            }
+        }
+    }
+
+    void generate_enum(code_generator& generator, const cpp_enum& e)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(e), true);
+        if (output)
+        {
+            output << keyword("enum");
+            if (e.is_scoped())
+                output << whitespace << keyword("class");
+            output << whitespace << identifier(e.name());
+            if (e.underlying_type())
+            {
+                output << newl << punctuation(":");
+                detail::write_type(output, e.underlying_type().value(), "");
+            }
+
+            if (e.is_definition())
+            {
+                output << punctuation("{");
+                output.indent();
+
+                auto need_sep = write_container(output, e, [](code_generator::output& out) {
+                    out << punctuation(",") << newl;
+                });
+                if (need_sep)
+                    output << newl;
+
+                output.unindent();
+                output << punctuation("};") << newl;
+            }
+            else
+                output << punctuation(";") << newl;
+        }
+    }
+
+    void generate_access_specifier(code_generator& generator, const cpp_access_specifier& access)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(access), false);
+        if (output)
+        {
+            output.unindent();
+            output << keyword(to_string(access.access_specifier())) << punctuation(":");
+            output.indent(false);
+        }
+    }
+
+    void generate_base_class(code_generator& generator, const cpp_base_class& base)
+    {
+        DEBUG_ASSERT(base.parent() && base.parent().value().kind() == cpp_entity_kind::class_t,
+                     detail::assert_handler{});
+        auto parent_kind = static_cast<const cpp_class&>(base.parent().value()).class_kind();
+
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(base), false);
+        if (output)
+        {
+            if (base.is_virtual())
+                output << keyword("virtual") << whitespace;
+
+            auto access = base.access_specifier();
+            if (access == cpp_protected)
+                output << keyword("protected") << whitespace;
+            else if (access == cpp_private && parent_kind != cpp_class_kind::class_t)
+                output << keyword("private") << whitespace;
+            else if (access == cpp_public && parent_kind == cpp_class_kind::class_t)
+                output << keyword("public") << whitespace;
+
+            output << identifier(base.name());
+        }
+    }
+
+    void write_specialization_arguments(code_generator::output&            output,
+                                        const cpp_template_specialization& spec)
+    {
+        if (spec.arguments_exposed())
+            detail::write_template_arguments(output, spec.arguments());
+        else if (!spec.unexposed_arguments().empty())
+            output << punctuation("<") << token_seq(spec.unexposed_arguments()) << punctuation(">");
+    }
+
+    void generate_class(code_generator& generator, const cpp_class& c,
+                        type_safe::optional_ref<const cpp_template_specialization> spec = nullptr)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(c), true);
+        if (output)
+        {
+            output << keyword(to_string(c.class_kind())) << whitespace;
+
+            if (spec)
+            {
+                output << spec.value().primary_template();
+                write_specialization_arguments(output, spec.value());
+            }
+            else
+                output << identifier(c.name());
+
+            if (c.is_final())
+                output << whitespace << keyword("final");
+
+            if (c.is_declaration())
+                output << punctuation(";") << newl;
+            else
+            {
+                if (!c.bases().empty())
+                {
+                    output << newl << punctuation(":");
+
+                    auto need_sep = false;
+                    for (auto& base : c.bases())
+                    {
+                        if (need_sep)
+                            output << punctuation(",");
+                        else
+                            need_sep = true;
+                        generate_base_class(generator, base);
+                    }
+                }
+                output << punctuation("{");
+                output.indent();
+
+                auto need_sep = false;
+                auto last_access =
+                    c.class_kind() == cpp_class_kind::class_t ? cpp_private : cpp_public;
+                for (auto& member : c)
+                {
+                    if (member.kind() == cpp_entity_kind::access_specifier_t)
+                    {
+                        auto& access = static_cast<const cpp_access_specifier&>(member);
+                        if (access.access_specifier() != last_access)
+                        {
+                            if (need_sep)
+                                output << newl;
+                            else
+                                need_sep = true;
+                            generate_access_specifier(generator, access);
+                            last_access = access.access_specifier();
+                        }
+                    }
+                    else
+                    {
+                        if (need_sep)
+                            output << newl;
+                        else
+                            need_sep = true;
+                        generate_code(generator, member);
+                    }
+                }
+
+                output.unindent();
+                output << punctuation("};") << newl;
+            }
+        }
+    }
+
+    void write_variable_base(code_generator::output& output, const cpp_variable_base& var,
+                             const std::string& name)
+    {
+        detail::write_type(output, var.type(), name);
+
+        if (var.default_value())
+        {
+            output << punctuation("=");
+            detail::write_expression(output, var.default_value().value());
+        }
+    }
+
+    void write_storage_class(code_generator::output& output, cpp_storage_class_specifiers storage,
+                             bool is_constexpr)
+    {
+        if (is_static(storage))
+            output << keyword("static") << whitespace;
+        if (is_extern(storage))
+            output << keyword("extern") << whitespace;
+        if (is_thread_local(storage))
+            output << keyword("thread_local") << whitespace;
+        if (is_constexpr)
+            output << keyword("constexpr") << whitespace;
+    }
+
+    void generate_variable(code_generator& generator, const cpp_variable& var)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        if (output)
+        {
+            write_storage_class(output, var.storage_class(), var.is_constexpr());
+
+            write_variable_base(output, var, var.name());
+            output << punctuation(";") << newl;
+        }
+    }
+
+    void generate_member_variable(code_generator& generator, const cpp_member_variable& var)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        if (output)
+        {
+            if (var.is_mutable())
+                output << keyword("mutable") << whitespace;
+            write_variable_base(output, var, var.name());
+            output << punctuation(";") << newl;
+        }
+    }
+
+    void generate_bitfield(code_generator& generator, const cpp_bitfield& var)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        if (output)
+        {
+            if (var.is_mutable())
+                output << keyword("mutable") << whitespace;
+            write_variable_base(output, var, var.name());
+            output << punctuation(":") << int_literal(std::to_string(var.no_bits()));
+            output << punctuation(";") << newl;
+        }
+    }
+
+    void generate_function_parameter(code_generator& generator, const cpp_function_parameter& param)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param), false);
+        if (output)
+            write_variable_base(output, param, param.name());
+    }
+
+    void write_function_parameters(code_generator::output& output, const cpp_function_base& base)
+    {
+        output << punctuation("(");
+        auto need_sep = write_container(output, base, punctuation(","));
+        if (base.is_variadic())
+        {
+            if (need_sep)
+                output << punctuation(",");
+            output << punctuation("...");
+        }
+        output << punctuation(")");
+    }
+
+    void write_noexcept(code_generator::output& output, const cpp_function_base& base, bool need_ws)
+    {
+        if (!base.noexcept_condition())
+            return;
+        else if (need_ws)
+            output << whitespace;
+
+        auto& cond = base.noexcept_condition().value();
+        if (cond.kind() == cpp_expression_kind::literal_t
+            && static_cast<const cpp_literal_expression&>(cond).value() == "true")
+            output << keyword("noexcept");
+        else
+        {
+            output << keyword("noexcept") << punctuation("(");
+            detail::write_expression(output, cond);
+            output << punctuation(")");
+        }
+    }
+
+    void write_function_body(code_generator::output& output, const cpp_function_base& base,
+                             bool is_pure_virtual)
+    {
+        switch (base.body_kind())
+        {
+        case cpp_function_declaration:
+        case cpp_function_definition:
+            if (is_pure_virtual)
+                output << punctuation("=") << int_literal("0");
+            output << punctuation(";") << newl;
+            break;
+
+        case cpp_function_defaulted:
+            output << punctuation("=") << keyword("default") << punctuation(";") << newl;
+            break;
+        case cpp_function_deleted:
+            output << punctuation("=") << keyword("delete") << punctuation(";") << newl;
+            break;
+        }
+    }
+
+    void generate_function(
+        code_generator& generator, const cpp_function& func,
+        type_safe::optional_ref<const cpp_template_specialization> spec = nullptr)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func), true);
+        if (output)
+        {
+            if (func.is_friend())
+                output << keyword("friend") << whitespace;
+            write_storage_class(output, func.storage_class(), func.is_constexpr());
+
+            if (detail::is_complex_type(func.return_type()))
+                output << keyword("auto") << whitespace;
+            else
+            {
+                detail::write_type(output, func.return_type(), "");
+                output << whitespace;
+            }
+
+            if (spec)
+            {
+                output << spec.value().primary_template();
+                write_specialization_arguments(output, spec.value());
+            }
+            else
+                output << identifier(func.name());
+            write_function_parameters(output, func);
+            write_noexcept(output, func, false);
+
+            if (detail::is_complex_type(func.return_type()))
+            {
+                output << punctuation("->");
+                detail::write_type(output, func.return_type(), "");
+            }
+            write_function_body(output, func, false);
+        }
+    }
+
+    void write_prefix_virtual(code_generator::output& output, const cpp_virtual& virt)
+    {
+        if (is_virtual(virt))
+            output << keyword("virtual") << whitespace;
+    }
+
+    void write_suffix_virtual(code_generator::output& output, const cpp_virtual& virt)
+    {
+        if (is_overriding(virt))
+            output << whitespace << keyword("override");
+        if (is_final(virt))
+            output << whitespace << keyword("final");
+    }
+
+    bool write_cv_ref(code_generator::output& output, const cpp_member_function_base& base)
+    {
+        auto need_ws = false;
+        switch (base.cv_qualifier())
+        {
+        case cpp_cv_none:
+            break;
+        case cpp_cv_const:
+            output << keyword("const");
+            need_ws = true;
+            break;
+        case cpp_cv_volatile:
+            output << keyword("volatile");
+            need_ws = true;
+            break;
+        case cpp_cv_const_volatile:
+            output << keyword("const") << whitespace << keyword("volatile");
+            need_ws = true;
+            break;
+        }
+
+        switch (base.ref_qualifier())
+        {
+        case cpp_ref_none:
+            break;
+        case cpp_ref_lvalue:
+            output << punctuation("&");
+            need_ws = false;
+            break;
+        case cpp_ref_rvalue:
+            output << punctuation("&&");
+            need_ws = false;
+            break;
+        }
+
+        return need_ws;
+    }
+
+    void generate_member_function(
+        code_generator& generator, const cpp_member_function& func,
+        type_safe::optional_ref<const cpp_template_specialization> spec = nullptr)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func), true);
+        if (output)
+        {
+            if (func.is_constexpr())
+                output << keyword("constexpr") << whitespace;
+            else
+                write_prefix_virtual(output, func.virtual_info());
+
+            if (detail::is_complex_type(func.return_type()))
+                output << keyword("auto") << whitespace;
+            else
+            {
+                detail::write_type(output, func.return_type(), "");
+                output << whitespace;
+            }
+
+            if (spec)
+            {
+                output << spec.value().primary_template();
+                write_specialization_arguments(output, spec.value());
+            }
+            else
+                output << identifier(func.name());
+            write_function_parameters(output, func);
+            auto need_ws = write_cv_ref(output, func);
+            write_noexcept(output, func, need_ws);
+
+            if (detail::is_complex_type(func.return_type()))
+            {
+                output << punctuation("->");
+                detail::write_type(output, func.return_type(), "");
+            }
+
+            write_suffix_virtual(output, func.virtual_info());
+            write_function_body(output, func, is_pure(func.virtual_info()));
+        }
+    }
+
+    void generate_conversion_op(code_generator& generator, const cpp_conversion_op& op)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(op), true);
+        if (output)
+        {
+            if (op.is_explicit())
+                output << keyword("explicit") << whitespace;
+            if (op.is_constexpr())
+                output << keyword("constexpr") << whitespace;
+            else
+                write_prefix_virtual(output, op.virtual_info());
+
+            auto pos = op.name().find("operator");
+            output << identifier(op.name().substr(0u, pos)) << keyword("operator") << whitespace;
+            detail::write_type(output, op.return_type(), "");
+            output << punctuation("(") << punctuation(")");
+            auto need_ws = write_cv_ref(output, op);
+            write_noexcept(output, op, need_ws);
+
+            write_suffix_virtual(output, op.virtual_info());
+            write_function_body(output, op, is_pure(op.virtual_info()));
+        }
+    }
+
+    void generate_constructor(code_generator& generator, const cpp_constructor& ctor)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(ctor), true);
+        if (output)
+        {
+            if (ctor.is_explicit())
+                output << keyword("explicit") << whitespace;
+            if (ctor.is_constexpr())
+                output << keyword("constexpr") << whitespace;
+
+            output << identifier(ctor.name());
+            write_function_parameters(output, ctor);
+            write_noexcept(output, ctor, false);
+
+            write_function_body(output, ctor, false);
+        }
+    }
+
+    void generate_destructor(code_generator& generator, const cpp_destructor& dtor)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(dtor), true);
+        if (output)
+        {
+            write_prefix_virtual(output, dtor.virtual_info());
+            output << identifier(dtor.name()) << punctuation("(") << punctuation(")");
+            write_noexcept(output, dtor, false);
+
+            write_suffix_virtual(output, dtor.virtual_info());
+            write_function_body(output, dtor, is_pure(dtor.virtual_info()));
+        }
+    }
+
+    void generate_function_base(code_generator& generator, const cpp_function_base& base,
+                                const cpp_template_specialization& spec)
+    {
+        switch (base.kind())
+        {
+        case cpp_entity_kind::function_t:
+            generate_function(generator, static_cast<const cpp_function&>(base),
+                              type_safe::ref(spec));
+            break;
+        case cpp_entity_kind::member_function_t:
+            generate_member_function(generator, static_cast<const cpp_member_function&>(base),
+                                     type_safe::ref(spec));
+            break;
+        case cpp_entity_kind::conversion_op_t:
+            generate_conversion_op(generator, static_cast<const cpp_conversion_op&>(base));
+            break;
+        case cpp_entity_kind::constructor_t:
+            generate_constructor(generator, static_cast<const cpp_constructor&>(base));
+            break;
+
+        default:
+            DEBUG_UNREACHABLE(detail::assert_handler{});
+            break;
+        }
+    }
+
+    void generate_template_type_parameter(code_generator&                    generator,
+                                          const cpp_template_type_parameter& param)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param), false);
+        if (output)
+        {
+            output << keyword(to_string(param.keyword()));
+            if (param.is_variadic())
+                output << punctuation("...");
+            if (!param.name().empty())
+                output << whitespace << identifier(param.name());
+            if (param.default_type())
+            {
+                output << punctuation("=");
+                detail::write_type(output, param.default_type().value(), "");
+            }
+        }
+    }
+
+    void generate_non_type_template_parameter(code_generator&                        generator,
+                                              const cpp_non_type_template_parameter& param)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param), false);
+        if (output)
+        {
+            detail::write_type(output, param.type(), param.name(), param.is_variadic());
+            if (param.default_value())
+            {
+                output << punctuation("=");
+                detail::write_expression(output, param.default_value().value());
+            }
+        }
+    }
+
+    void generate_template_template_parameter(code_generator&                        generator,
+                                              const cpp_template_template_parameter& param)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param), true);
+        if (output)
+        {
+            output << keyword("template") << punctuation("<");
+            write_container(output, param, punctuation(","));
+            output << punctuation(">") << keyword(to_string(param.keyword())) << whitespace;
+            if (param.is_variadic())
+                output << punctuation("...");
+            output << identifier(param.name());
+            if (param.default_template())
+                output << punctuation("=") << param.default_template().value();
+        }
+    }
+
+    void write_template_parameters(code_generator::output& output, const cpp_template& templ)
+    {
+        output << keyword("template") << punctuation("<");
+        auto need_sep = false;
+        for (auto& param : templ.parameters())
+        {
+            if (need_sep)
+                output << punctuation(",");
+            else
+                need_sep = true;
+            generate_code(*output.generator(), param);
+        }
+        output << punctuation(">") << newl;
+    }
+
+    void generate_alias_template(code_generator& generator, const cpp_alias_template& alias)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), true);
+        if (output)
+        {
+            write_template_parameters(output, alias);
+            generate_code(generator, alias.type_alias());
+        }
+    }
+
+    void generate_variable_template(code_generator& generator, const cpp_variable_template& var)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), true);
+        if (output)
+        {
+            write_template_parameters(output, var);
+            generate_code(generator, var.variable());
+        }
+    }
+
+    void generate_function_template(code_generator& generator, const cpp_function_template& func)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func), true);
+        if (output)
+        {
+            write_template_parameters(output, func);
+            generate_code(generator, func.function());
+        }
+    }
+
+    void generate_function_template_specialization(code_generator& generator,
+                                                   const cpp_function_template_specialization& func)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func), true);
+        if (output)
+        {
+            write_template_parameters(output, func);
+            generate_function_base(generator, func.function(), func);
+        }
+    }
+
+    void generate_class_template(code_generator& generator, const cpp_class_template& templ)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(templ), true);
+        if (output)
+        {
+            write_template_parameters(output, templ);
+            generate_class(generator, templ.class_());
+        }
+    }
+
+    void generate_class_template_specialization(code_generator&                          generator,
+                                                const cpp_class_template_specialization& templ)
+    {
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(templ), true);
+        if (output)
+        {
+            write_template_parameters(output, templ);
+            generate_class(generator, templ.class_(), type_safe::ref(templ));
+        }
+    }
+}
+
+void cppast::generate_code(code_generator& generator, const cpp_entity& e)
+{
+    switch (e.kind())
+    {
+#define CPPAST_DETAIL_HANDLE(Name)                                                                 \
+    case cpp_entity_kind::Name##_t:                                                                \
+        generate_##Name(generator, static_cast<const cpp_##Name&>(e));                             \
+        break;
+
+        CPPAST_DETAIL_HANDLE(file)
+
+        CPPAST_DETAIL_HANDLE(macro_definition)
+        CPPAST_DETAIL_HANDLE(include_directive)
+
+        CPPAST_DETAIL_HANDLE(language_linkage)
+        CPPAST_DETAIL_HANDLE(namespace)
+        CPPAST_DETAIL_HANDLE(namespace_alias)
+        CPPAST_DETAIL_HANDLE(using_directive)
+        CPPAST_DETAIL_HANDLE(using_declaration)
+
+        CPPAST_DETAIL_HANDLE(type_alias)
+
+        CPPAST_DETAIL_HANDLE(enum)
+        CPPAST_DETAIL_HANDLE(enum_value)
+
+        CPPAST_DETAIL_HANDLE(class)
+        CPPAST_DETAIL_HANDLE(access_specifier)
+        CPPAST_DETAIL_HANDLE(base_class)
+
+        CPPAST_DETAIL_HANDLE(variable)
+        CPPAST_DETAIL_HANDLE(member_variable)
+        CPPAST_DETAIL_HANDLE(bitfield)
+
+        CPPAST_DETAIL_HANDLE(function_parameter)
+        CPPAST_DETAIL_HANDLE(function)
+        CPPAST_DETAIL_HANDLE(member_function)
+        CPPAST_DETAIL_HANDLE(conversion_op)
+        CPPAST_DETAIL_HANDLE(constructor)
+        CPPAST_DETAIL_HANDLE(destructor)
+
+        CPPAST_DETAIL_HANDLE(template_type_parameter)
+        CPPAST_DETAIL_HANDLE(non_type_template_parameter)
+        CPPAST_DETAIL_HANDLE(template_template_parameter)
+
+        CPPAST_DETAIL_HANDLE(alias_template)
+        CPPAST_DETAIL_HANDLE(variable_template)
+        CPPAST_DETAIL_HANDLE(function_template)
+        CPPAST_DETAIL_HANDLE(function_template_specialization)
+        CPPAST_DETAIL_HANDLE(class_template)
+        CPPAST_DETAIL_HANDLE(class_template_specialization)
+
+#undef CPPAST_DETAIL_HANDLE
+
+    case cpp_entity_kind::count:
+        DEBUG_UNREACHABLE(detail::assert_handler{});
+        break;
+    }
+}
+
+void detail::write_template_arguments(code_generator::output&                           output,
+                                      type_safe::array_ref<const cpp_template_argument> arguments)
+{
+    if (arguments.size() == 0u)
+        return;
+
+    output << punctuation("<");
+    auto need_sep = false;
+    for (auto& arg : arguments)
+    {
+        if (need_sep)
+            output << punctuation(",");
+        else
+            need_sep = true;
+
+        if (auto type = arg.type())
+            detail::write_type(output, type.value(), "");
+        else if (auto expr = arg.expression())
+            detail::write_expression(output, expr.value());
+        else if (auto templ = arg.template_ref())
+            output << templ.value();
+        else
+            DEBUG_UNREACHABLE(detail::assert_handler{});
+    }
+    output << punctuation(">");
+}

src/cpp_expression.cpp

@@ -0,0 +1,93 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#include <cppast/cpp_expression.hpp>
+
+using namespace cppast;
+
+namespace
+{
+    void write_literal(code_generator::output& output, const cpp_literal_expression& expr)
+    {
+        auto type_kind = cpp_void;
+        if (expr.type().kind() == cpp_type_kind::builtin_t)
+            type_kind = static_cast<const cpp_builtin_type&>(expr.type()).builtin_type_kind();
+        else if (expr.type().kind() == cpp_type_kind::pointer_t)
+        {
+            auto& pointee = static_cast<const cpp_pointer_type&>(expr.type()).pointee();
+            if (pointee.kind() == cpp_type_kind::builtin_t)
+            {
+                auto& builtin_pointee = static_cast<const cpp_builtin_type&>(pointee);
+                if (builtin_pointee.builtin_type_kind() == cpp_char
+                    || builtin_pointee.builtin_type_kind() == cpp_wchar
+                    || builtin_pointee.builtin_type_kind() == cpp_char16
+                    || builtin_pointee.builtin_type_kind() == cpp_char32)
+                    // pointer to char aka string
+                    type_kind = builtin_pointee.builtin_type_kind();
+            }
+        }
+
+        switch (type_kind)
+        {
+        case cpp_void:
+            output << token_seq(expr.value());
+            break;
+
+        case cpp_bool:
+            output << keyword(expr.value());
+            break;
+
+        case cpp_uchar:
+        case cpp_ushort:
+        case cpp_uint:
+        case cpp_ulong:
+        case cpp_ulonglong:
+        case cpp_uint128:
+        case cpp_schar:
+        case cpp_short:
+        case cpp_int:
+        case cpp_long:
+        case cpp_longlong:
+        case cpp_int128:
+            output << int_literal(expr.value());
+            break;
+
+        case cpp_float:
+        case cpp_double:
+        case cpp_longdouble:
+        case cpp_float128:
+            output << float_literal(expr.value());
+            break;
+
+        case cpp_char:
+        case cpp_wchar:
+        case cpp_char16:
+        case cpp_char32:
+            output << string_literal(expr.value());
+            break;
+
+        case cpp_nullptr:
+            output << keyword(expr.value());
+            break;
+        }
+    }
+
+    void write_unexposed(code_generator::output& output, const cpp_unexposed_expression& expr)
+    {
+        output << token_seq(expr.expression());
+    }
+}
+
+void detail::write_expression(code_generator::output& output, const cpp_expression& expr)
+{
+    switch (expr.kind())
+    {
+    case cpp_expression_kind::literal_t:
+        write_literal(output, static_cast<const cpp_literal_expression&>(expr));
+        break;
+    case cpp_expression_kind::unexposed_t:
+        write_unexposed(output, static_cast<const cpp_unexposed_expression&>(expr));
+        break;
+    }
+}

src/cpp_type.cpp

@@ -5,6 +5,7 @@
 #include <cppast/cpp_type.hpp>
 
 #include <cppast/cpp_array_type.hpp>
+#include <cppast/cpp_decltype_type.hpp>
 #include <cppast/cpp_entity.hpp>
 #include <cppast/cpp_entity_kind.hpp>
 #include <cppast/cpp_function_type.hpp>
@@ -91,3 +92,382 @@ std::unique_ptr<cpp_dependent_type> cpp_dependent_type::build(
     return std::unique_ptr<cpp_dependent_type>(
         new cpp_dependent_type(std::move(name), std::move(dependee)));
 }
+
+namespace
+{
+    // is directly a complex type
+    // is_complex_type also checks for children
+    bool is_direct_complex(const cpp_type& type) noexcept
+    {
+        switch (type.kind())
+        {
+        case cpp_type_kind::builtin_t:
+        case cpp_type_kind::user_defined_t:
+        case cpp_type_kind::auto_t:
+        case cpp_type_kind::decltype_t:
+        case cpp_type_kind::decltype_auto_t:
+        case cpp_type_kind::cv_qualified_t:
+        case cpp_type_kind::pointer_t:
+        case cpp_type_kind::reference_t:
+        case cpp_type_kind::template_parameter_t:
+        case cpp_type_kind::template_instantiation_t:
+        case cpp_type_kind::dependent_t:
+        case cpp_type_kind::unexposed_t:
+            return false;
+
+        case cpp_type_kind::array_t:
+        case cpp_type_kind::function_t:
+        case cpp_type_kind::member_function_t:
+        case cpp_type_kind::member_object_t:
+            return true;
+        }
+
+        DEBUG_UNREACHABLE(detail::assert_handler{});
+        return false;
+    }
+}
+
+bool detail::is_complex_type(const cpp_type& type) noexcept
+{
+    switch (type.kind())
+    {
+    case cpp_type_kind::cv_qualified_t:
+        return is_complex_type(static_cast<const cpp_cv_qualified_type&>(type).type());
+    case cpp_type_kind::pointer_t:
+        return is_complex_type(static_cast<const cpp_pointer_type&>(type).pointee());
+    case cpp_type_kind::reference_t:
+        return is_complex_type(static_cast<const cpp_reference_type&>(type).referee());
+
+    default:
+        break;
+    }
+
+    return is_direct_complex(type);
+}
+
+namespace
+{
+    void write_builtin(code_generator::output& output, const cpp_builtin_type& type)
+    {
+        output << keyword(to_string(type.builtin_type_kind()));
+    }
+
+    void write_user_defined(code_generator::output& output, const cpp_user_defined_type& type)
+    {
+        output << type.entity();
+    }
+
+    void write_auto(code_generator::output& output, const cpp_auto_type&)
+    {
+        output << keyword("auto");
+    }
+
+    void write_decltype(code_generator::output& output, const cpp_decltype_type& type)
+    {
+        output << keyword("decltype") << punctuation("(");
+        detail::write_expression(output, type.expression());
+        output << punctuation(")");
+    }
+
+    void write_decltype_auto(code_generator::output& output, const cpp_decltype_auto_type&)
+    {
+        output << keyword("decltype") << punctuation("(") << keyword("auto") << punctuation(")");
+    }
+
+    void write_cv_qualified_prefix(code_generator::output&      output,
+                                   const cpp_cv_qualified_type& type)
+    {
+        detail::write_type_prefix(output, type.type());
+
+        if (is_direct_complex(type.type()))
+            output << punctuation("(");
+
+        if (is_const(type.cv_qualifier()))
+            output << whitespace << keyword("const");
+        if (is_volatile(type.cv_qualifier()))
+            output << whitespace << keyword("volatile");
+    }
+
+    void write_cv_qualified_suffix(code_generator::output&      output,
+                                   const cpp_cv_qualified_type& type)
+    {
+        if (is_direct_complex(type.type()))
+            output << punctuation(")");
+        detail::write_type_suffix(output, type.type());
+    }
+
+    bool pointer_requires_paren(const cpp_pointer_type& type)
+    {
+        auto kind = type.pointee().kind();
+        return kind == cpp_type_kind::function_t || kind == cpp_type_kind::array_t;
+    }
+
+    void write_pointer_prefix(code_generator::output& output, const cpp_pointer_type& type)
+    {
+        detail::write_type_prefix(output, type.pointee());
+        if (pointer_requires_paren(type))
+            output << punctuation("(");
+
+        output << punctuation("*");
+    }
+
+    void write_pointer_suffix(code_generator::output& output, const cpp_pointer_type& type)
+    {
+        if (pointer_requires_paren(type))
+            output << punctuation(")");
+        detail::write_type_suffix(output, type.pointee());
+    }
+
+    void write_reference_prefix(code_generator::output& output, const cpp_reference_type& type)
+    {
+        detail::write_type_prefix(output, type.referee());
+        if (is_direct_complex(type.referee()))
+            output << punctuation("(");
+
+        if (type.reference_kind() == cpp_ref_lvalue)
+            output << punctuation("&");
+        else if (type.reference_kind() == cpp_ref_rvalue)
+            output << punctuation("&&");
+        else
+            DEBUG_UNREACHABLE(detail::assert_handler{});
+    }
+
+    void write_reference_suffix(code_generator::output& output, const cpp_reference_type& type)
+    {
+        if (is_direct_complex(type.referee()))
+            output << punctuation(")");
+        detail::write_type_suffix(output, type.referee());
+    }
+
+    void write_array_prefix(code_generator::output& output, const cpp_array_type& type)
+    {
+        detail::write_type_prefix(output, type.value_type());
+    }
+
+    void write_array_suffix(code_generator::output& output, const cpp_array_type& type)
+    {
+        output << punctuation("[");
+        if (type.size())
+            detail::write_expression(output, type.size().value());
+        output << punctuation("]");
+        detail::write_type_suffix(output, type.value_type());
+    }
+
+    void write_function_prefix(code_generator::output& output, const cpp_function_type& type)
+    {
+        detail::write_type_prefix(output, type.return_type());
+    }
+
+    template <typename T>
+    void write_parameters(code_generator::output& output, const T& type)
+    {
+        output << punctuation("(");
+
+        auto need_sep = false;
+        for (auto& param : type.parameter_types())
+        {
+            if (need_sep)
+                output << punctuation(",");
+            else
+                need_sep = true;
+            detail::write_type_prefix(output, param);
+            detail::write_type_suffix(output, param);
+        }
+        if (type.is_variadic())
+        {
+            if (need_sep)
+                output << punctuation(",");
+            output << punctuation("...");
+        }
+
+        output << punctuation(")");
+    }
+
+    void write_function_suffix(code_generator::output& output, const cpp_function_type& type)
+    {
+        write_parameters(output, type);
+
+        detail::write_type_suffix(output, type.return_type());
+    }
+
+    const cpp_type& strip_class_type(const cpp_type& type, cpp_cv* cv, cpp_reference* ref)
+    {
+        if (type.kind() == cpp_type_kind::cv_qualified_t)
+        {
+            auto& cv_qual = static_cast<const cpp_cv_qualified_type&>(type);
+            if (cv)
+                *cv = cv_qual.cv_qualifier();
+            return strip_class_type(cv_qual.type(), cv, ref);
+        }
+        else if (type.kind() == cpp_type_kind::reference_t)
+        {
+            auto& ref_type = static_cast<const cpp_reference_type&>(type);
+            if (ref)
+                *ref = ref_type.reference_kind();
+            return strip_class_type(ref_type.referee(), cv, ref);
+        }
+        else
+        {
+            DEBUG_ASSERT(!detail::is_complex_type(type), detail::assert_handler{});
+            return type;
+        }
+    }
+
+    void write_member_function_prefix(code_generator::output&         output,
+                                      const cpp_member_function_type& type)
+    {
+        detail::write_type_prefix(output, type.return_type());
+
+        output << punctuation("(");
+        detail::write_type_prefix(output, strip_class_type(type.class_type(), nullptr, nullptr));
+        output << punctuation("::");
+    }
+
+    void write_member_function_suffix(code_generator::output&         output,
+                                      const cpp_member_function_type& type)
+    {
+        output << punctuation(")");
+        write_parameters(output, type);
+
+        auto cv  = cpp_cv_none;
+        auto ref = cpp_ref_none;
+        strip_class_type(type.class_type(), &cv, &ref);
+
+        if (cv == cpp_cv_const_volatile)
+            output << keyword("const") << whitespace << keyword("volatile");
+        else if (is_const(cv))
+            output << keyword("const");
+        else if (is_volatile(cv))
+            output << keyword("volatile");
+
+        if (ref == cpp_ref_lvalue)
+            output << punctuation("&");
+        else if (ref == cpp_ref_rvalue)
+            output << punctuation("&&");
+
+        detail::write_type_suffix(output, type.return_type());
+    }
+
+    void write_member_object_prefix(code_generator::output&       output,
+                                    const cpp_member_object_type& type)
+    {
+        detail::write_type_prefix(output, type.object_type());
+        output << punctuation("(");
+        DEBUG_ASSERT(!detail::is_complex_type(type.class_type()), detail::assert_handler{});
+        detail::write_type_prefix(output, type.class_type());
+        output << punctuation("::");
+    }
+
+    void write_member_object_suffix(code_generator::output& output, const cpp_member_object_type&)
+    {
+        output << punctuation(")");
+    }
+
+    void write_template_parameter(code_generator::output&            output,
+                                  const cpp_template_parameter_type& type)
+    {
+        output << type.entity();
+    }
+
+    void write_template_instantiation(code_generator::output&                output,
+                                      const cpp_template_instantiation_type& type)
+    {
+        output << type.primary_template();
+        if (type.arguments_exposed())
+            detail::write_template_arguments(output, type.arguments());
+        else
+            output << punctuation("<") << token_seq(type.unexposed_arguments()) << punctuation(">");
+    }
+
+    void write_dependent(code_generator::output& output, const cpp_dependent_type& type)
+    {
+        output << token_seq(type.name());
+    }
+
+    void write_unexposed(code_generator::output& output, const cpp_unexposed_type& type)
+    {
+        output << token_seq(type.name());
+    }
+}
+
+void detail::write_type_prefix(code_generator::output& output, const cpp_type& type)
+{
+    switch (type.kind())
+    {
+#define CPPAST_DETAIL_HANDLE(Name)                                                                 \
+    case cpp_type_kind::Name##_t:                                                                  \
+        write_##Name(output, static_cast<const cpp_##Name##_type&>(type));                         \
+        break;
+
+#define CPPAST_DETAIL_HANDLE_COMPLEX(Name)                                                         \
+    case cpp_type_kind::Name##_t:                                                                  \
+        write_##Name##_prefix(output, static_cast<const cpp_##Name##_type&>(type));                \
+        break;
+
+        CPPAST_DETAIL_HANDLE(builtin)
+        CPPAST_DETAIL_HANDLE(user_defined)
+        CPPAST_DETAIL_HANDLE(auto)
+        CPPAST_DETAIL_HANDLE(decltype)
+        CPPAST_DETAIL_HANDLE(decltype_auto)
+        CPPAST_DETAIL_HANDLE_COMPLEX(cv_qualified)
+        CPPAST_DETAIL_HANDLE_COMPLEX(pointer)
+        CPPAST_DETAIL_HANDLE_COMPLEX(reference)
+        CPPAST_DETAIL_HANDLE_COMPLEX(array)
+        CPPAST_DETAIL_HANDLE_COMPLEX(function)
+        CPPAST_DETAIL_HANDLE_COMPLEX(member_function)
+        CPPAST_DETAIL_HANDLE_COMPLEX(member_object)
+        CPPAST_DETAIL_HANDLE(template_parameter)
+        CPPAST_DETAIL_HANDLE(template_instantiation)
+        CPPAST_DETAIL_HANDLE(dependent)
+        CPPAST_DETAIL_HANDLE(unexposed)
+    }
+
+#undef CPPAST_DETAIL_HANDLE
+#undef CPPAST_DETAIL_HANDLE_COMPLEX
+}
+
+void detail::write_type_suffix(code_generator::output& output, const cpp_type& type)
+{
+    switch (type.kind())
+    {
+#define CPPAST_DETAIL_HANDLE(Name)                                                                 \
+    case cpp_type_kind::Name##_t:                                                                  \
+        break;
+
+#define CPPAST_DETAIL_HANDLE_COMPLEX(Name)                                                         \
+    case cpp_type_kind::Name##_t:                                                                  \
+        write_##Name##_suffix(output, static_cast<const cpp_##Name##_type&>(type));                \
+        break;
+
+        CPPAST_DETAIL_HANDLE(builtin)
+        CPPAST_DETAIL_HANDLE(user_defined)
+        CPPAST_DETAIL_HANDLE(auto)
+        CPPAST_DETAIL_HANDLE(decltype)
+        CPPAST_DETAIL_HANDLE(decltype_auto)
+        CPPAST_DETAIL_HANDLE_COMPLEX(cv_qualified)
+        CPPAST_DETAIL_HANDLE_COMPLEX(pointer)
+        CPPAST_DETAIL_HANDLE_COMPLEX(reference)
+        CPPAST_DETAIL_HANDLE_COMPLEX(array)
+        CPPAST_DETAIL_HANDLE_COMPLEX(function)
+        CPPAST_DETAIL_HANDLE_COMPLEX(member_function)
+        CPPAST_DETAIL_HANDLE_COMPLEX(member_object)
+        CPPAST_DETAIL_HANDLE(template_parameter)
+        CPPAST_DETAIL_HANDLE(template_instantiation)
+        CPPAST_DETAIL_HANDLE(dependent)
+        CPPAST_DETAIL_HANDLE(unexposed)
+    }
+
+#undef CPPAST_DETAIL_HANDLE
+#undef CPPAST_DETAIL_HANDLE_COMPLEX
+}
+
+void detail::write_type(code_generator::output& output, const cpp_type& type, std::string name,
+                        bool is_variadic)
+{
+    write_type_prefix(output, type);
+    if (!name.empty())
+        output << whitespace << identifier(name);
+    if (is_variadic)
+        output << punctuation("...");
+    write_type_suffix(output, type);
+}

src/libclang/function_parser.cpp

@@ -17,7 +17,7 @@ namespace
     {
         auto name        = detail::get_cursor_name(cur);
         auto type        = detail::parse_type(context, cur, clang_getCursorType(cur));
-        auto is_decltype = type->kind() == cpp_type_kind::decltype_;
+        auto is_decltype = type->kind() == cpp_type_kind::decltype_t;
 
         std::unique_ptr<cpp_expression> default_value;
         detail::visit_children(cur, [&](const CXCursor& child) {

src/libclang/preprocessor.cpp

@@ -299,13 +299,13 @@ namespace
         return result;
     }
 
-    bool bump_c_comment(position& p, detail::preprocessor_output& output)
+    bool bump_c_comment(position& p, detail::preprocessor_output& output, bool in_main_file)
     {
         if (!starts_with(p, "/*"))
             return false;
         p.bump(2u);
 
-        if (starts_with(p, "*"))
+        if (in_main_file && starts_with(p, "*"))
         {
             // doc comment
             p.bump();
@@ -371,20 +371,20 @@ namespace
         }
     }
 
-    bool bump_cpp_comment(position& p, detail::preprocessor_output& output)
+    bool bump_cpp_comment(position& p, detail::preprocessor_output& output, bool in_main_file)
     {
         if (!starts_with(p, "//"))
             return false;
         p.bump(2u);
 
-        if (starts_with(p, "/") || starts_with(p, "!"))
+        if (in_main_file && (starts_with(p, "/") || starts_with(p, "!")))
         {
             // C++ style doc comment
             p.bump();
             auto comment = parse_cpp_doc_comment(p, false);
             merge_or_add(output, std::move(comment));
         }
-        else if (starts_with(p, "<"))
+        else if (in_main_file && starts_with(p, "<"))
         {
             // end of line doc comment
             p.bump();
@@ -408,7 +408,8 @@ namespace
     }
 
     std::unique_ptr<cpp_macro_definition> parse_macro(position&                    p,
-                                                      detail::preprocessor_output& output)
+                                                      detail::preprocessor_output& output,
+                                                      bool                         in_main_file)
     {
         // format (at new line): #define <name> [replacement]
         // or: #define <name>(<args>) [replacement]
@@ -446,6 +447,9 @@ namespace
         }
         // don't skip newline
 
+        if (!in_main_file)
+            return nullptr;
+
         auto result = cpp_macro_definition::build(std::move(name), std::move(args), std::move(rep));
         // match comment directly
         if (!output.comments.empty() && output.comments.back().matches(*result, p.cur_line()))
@@ -472,7 +476,8 @@ namespace
     }
 
     std::unique_ptr<cpp_include_directive> parse_include(position&                    p,
-                                                         detail::preprocessor_output& output)
+                                                         detail::preprocessor_output& output,
+                                                         bool                         in_main_file)
     {
         // format (at new line, literal <>): #include <filename>
         // or: #include "filename"
@@ -505,6 +510,9 @@ namespace
         DEBUG_ASSERT(starts_with(p, "\n"), detail::assert_handler{});
         // don't skip newline
 
+        if (!in_main_file)
+            return nullptr;
+
         auto result = cpp_include_directive::build(cpp_file_ref(cpp_entity_id(filename), filename),
                                                    include_kind);
         if (!output.comments.empty() && output.comments.back().matches(*result, p.cur_line()))
@@ -614,10 +622,9 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
     std::size_t file_depth = 0u;
     while (p)
     {
-        if (auto macro = parse_macro(p, result))
+        if (auto macro = parse_macro(p, result, file_depth == 0u))
         {
-            if (file_depth == 0u)
-                result.entities.push_back({std::move(macro), p.cur_line()});
+            result.entities.push_back({std::move(macro), p.cur_line()});
         }
         else if (auto undef = parse_undef(p))
         {
@@ -631,7 +638,7 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
                                           }),
                            result.entities.end());
         }
-        else if (auto include = parse_include(p, result))
+        else if (auto include = parse_include(p, result, file_depth == 0u))
         {
             if (file_depth == 0u)
                 result.entities.push_back({std::move(include), p.cur_line()});
@@ -669,9 +676,9 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
                 break;
             }
         }
-        else if (bump_c_comment(p, result))
+        else if (bump_c_comment(p, result, file_depth == 0u))
             continue;
-        else if (bump_cpp_comment(p, result))
+        else if (bump_cpp_comment(p, result, file_depth == 0u))
             continue;
         else
             p.bump();

test/code_generator.cpp

@@ -0,0 +1,39 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#include <cppast/code_generator.hpp>
+
+#include "test_parser.hpp"
+
+TEST_CASE("code_generator")
+{
+    // no need to check much here, as each entity check separately
+    // only write some file with equivalent code and synopsis
+    auto code = R"(using type=int;
+
+struct foo{
+  int a;
+
+  auto func(int)->int(*)[];
+
+private:
+  int const b=42;
+};
+
+int(*(foo::* mptr)(int))[];
+
+enum class bar
+:int{
+  a,
+  b=42
+};
+
+void func(int(*)(int));
+
+extern void(* ptr)(int(*)(int))=&func;
+)";
+
+    auto file = parse({}, "code_generator.cpp", code);
+    REQUIRE(get_code(*file) == code);
+}

test/cpp_alias_template.cpp

@@ -12,27 +12,43 @@ TEST_CASE("cpp_alias_template")
 {
     // no need to check advanced types here nor template parameters
     auto code = R"(
+/// template<typename T>
+/// using a=int;
 template <typename T>
 using a = int;
 
+/// template<int I,typename T=void>
+/// using b=T;
 template <int I, typename T = void>
 using b = T;
 
+/// template<typename T>
+/// using c=T const*;
 template <typename T>
 using c = const T*;
 
+/// template<typename T>
+/// using d=a<void>;
 template <typename T>
 using d = a<void>;
 
+/// template<int I>
+/// using e=b<I> const;
 template <int I>
 using e = const b<I>;
 
+/// template<int I>
+/// using f=b<I < a<int>{(0 , 1)}, int>;
 template <int I>
 using f = b<I < a<int>{(0,1)}, int>;
 
+/// template<typename T,template<typename>class Templ>
+/// using g=Templ<T>;
 template <typename T, template <typename> class Templ>
 using g = Templ<T>;
 
+/// template<typename T>
+/// using h=g<T, a>;
 template <typename T>
 using h = g<T, a>;
 )";

test/cpp_class.cpp

@@ -12,16 +12,40 @@ TEST_CASE("cpp_class")
 {
     auto code = R"(
 // forward declarations
+/// struct a;
 struct a;
+/// class b;
 class b;
+/// struct unresolved;
 struct unresolved;
 
 // basic
+/// struct a{
+/// };
 struct a {};
+/// class b final{
+/// };
 class b final {};
+/// union c{
+/// };
 union c {};
 
 // members
+/// struct d{
+///   enum m1{
+///   };
+///
+///   enum m2{
+///   };
+///
+/// private:
+///   enum m3{
+///   };
+///
+/// protected:
+///   enum m4{
+///   };
+/// };
 struct d
 {
     enum m1 {};
@@ -38,20 +62,31 @@ protected:
 };
 
 // bases
+/// class e
+/// :a,d{
+/// };
 class e
 : a, private d {};
 
 namespace ns
 {
+    /// struct base{
+    /// };
     struct base {};
 }
 
+/// struct f
+/// :ns::base,virtual protected e{
+/// };
 struct f
 : public ns::base, virtual protected e
 {};
 
 using namespace ns;
 
+/// struct g
+/// :base{
+/// };
 struct g
 : base {};
 )";

test/cpp_class_template.cpp

@@ -16,20 +16,45 @@ TEST_CASE("cpp_class_template")
 {
     auto code = R"(
 // check everything not related to members first
+/// template<typename T>
+/// class a{
+/// };
 template <typename T>
 class a {};
 
+/// template<int I,typename T>
+/// struct b{
+/// };
 template <int I, typename T>
 struct b {};
 
+/// template<template<typename>class T>
+/// union c;
 template <template <typename> class T>
 union c;
 
 // bases
+/// template<typename T>
+/// struct d
+/// :T,a<T>,T::type,a<T>::type{
+/// };
 template <typename T>
 struct d : T, a<T>, T::type, a<T>::type {};
 
 // members
+/// template<typename T>
+/// struct e{
+///   T var_a;
+///
+///   a<T> var_b;
+///
+///   typename T::type var_c;
+///
+///   typename a<T>::type var_d;
+///
+///   template<typename U>
+///   T func(U);
+/// };
 template <typename T>
 struct e
 {
@@ -43,16 +68,28 @@ struct e
 };
 
 // full specialization
+/// template<>
+/// class a<int>{
+/// };
 template <>
 class a<int> {};
 
+/// template<>
+/// struct b<0,int>{
+/// };
 template <>
 struct b<0, int> {};
 
 // partial specialization
+/// template<typename T>
+/// class a<T*>{
+/// };
 template <typename T>
 class a<T*> {};
 
+/// template<typename T>
+/// struct b<0,T>{
+/// };
 template <typename T>
 struct b<0, T> {};
 )";

test/cpp_enum.cpp

@@ -11,6 +11,12 @@ using namespace cppast;
 TEST_CASE("cpp_enum")
 {
     auto code = R"(
+/// enum a{
+///   a_a,
+///   a_b=42,
+///   a_c,
+///   a_d=a_a+2
+/// };
 enum a
 {
     a_a,
@@ -19,8 +25,15 @@ enum a
     a_d = a_a + 2,
 };
 
+/// enum class b;
 enum class b; // forward declaration
 
+/// enum class b
+/// :int{
+///   b_a,
+///   b_b=42,
+///   b_c
+/// };
 enum class b : int
 {
     b_a,
@@ -28,6 +41,8 @@ enum class b : int
     b_c
 };
 
+/// enum c
+/// :int;
 enum c : int;
 )";
 
@@ -54,7 +69,7 @@ enum c : int;
                     ++no_vals;
                     REQUIRE(val.value());
                     auto& expr = val.value().value();
-                    REQUIRE(expr.kind() == cpp_expression_kind::unexposed);
+                    REQUIRE(expr.kind() == cpp_expression_kind::unexposed_t);
                     REQUIRE(static_cast<const cpp_unexposed_expression&>(expr).expression()
                             == "42");
                     REQUIRE(equal_types(idx, expr.type(), *cpp_builtin_type::build(cpp_uint)));
@@ -65,7 +80,7 @@ enum c : int;
                     REQUIRE(val.value());
                     auto& expr = val.value().value();
                     // this is unexposed for some reason
-                    REQUIRE(expr.kind() == cpp_expression_kind::unexposed);
+                    REQUIRE(expr.kind() == cpp_expression_kind::unexposed_t);
                     REQUIRE(static_cast<const cpp_unexposed_expression&>(expr).expression()
                             == "a_a+2");
                     REQUIRE(equal_types(idx, expr.type(), *cpp_builtin_type::build(cpp_uint)));
@@ -99,7 +114,7 @@ enum c : int;
                         ++no_vals;
                         REQUIRE(val.value());
                         auto& expr = val.value().value();
-                        REQUIRE(expr.kind() == cpp_expression_kind::literal);
+                        REQUIRE(expr.kind() == cpp_expression_kind::literal_t);
                         REQUIRE(static_cast<const cpp_literal_expression&>(expr).value() == "42");
                         REQUIRE(equal_types(idx, expr.type(), *cpp_builtin_type::build(cpp_int)));
                     }

test/cpp_function.cpp

@@ -15,29 +15,42 @@ TEST_CASE("cpp_function")
 {
     auto code = R"(
 // parameters and return type are only tested here
+/// void a();
 void a();
+/// int b(int a,float* b=nullptr);
 int b(int a, float* b = nullptr);
+/// auto c(decltype(42) a,...)->int(&)[10];
 int (&c(decltype(42) a, ...))[10];
 
 // noexcept conditions
+/// void d()noexcept;
 void d() noexcept;
+/// void e()noexcept(false);
 void e() noexcept(false);
+/// void f()noexcept(noexcept(d()));
 void f() noexcept(noexcept(d()));
 
 // storage class + constexpr
+/// extern void g();
 extern void g();
+/// static void h();
 static void h();
+/// constexpr void i();
 constexpr void i();
+/// static constexpr void j();
 static constexpr void j();
 
 // body
 namespace ns
 {
+    /// void k()=delete;
     void k() = delete;
 
+    /// void l();
     void l();
 }
 
+/// void ns::l();
 void ns::l()
 {
     // might confuse parser
@@ -215,13 +228,17 @@ TEST_CASE("static cpp_function")
 // no need to test anything special
 struct foo
 {
+    /// static void a();
     static void a();
 
+    /// static int b()noexcept;
     static int b() noexcept { return 0; }
 
+    /// static constexpr char c()=delete;
     static constexpr char c() = delete;
 };
 
+/// static void foo::a();
 void foo::a() {}
 )";
 

test/cpp_function_template.cpp

@@ -17,36 +17,56 @@ TEST_CASE("cpp_function_template")
 template <int I>
 using type = int;
 
+/// template<typename T>
+/// T a(T const& t);
 template <typename T>
 T a(const T& t);
 
 struct d
 {
+    /// template<int I,typename T>
+    /// static type<I> b(T);
     template <int I, typename T>
     static type<I> b(T);
 
+    /// template<typename T=const int>
+    /// T c();
     template <typename T = const int>
     auto c() -> T;
 
+    /// template<typename T>
+    /// operator T()const;
     template <typename T>
     operator T() const;
 
+    /// template<typename T>
+    /// d(T const&);
     template <typename T>
     d(const T&);
 };
 
+/// template<>
+/// int a(int const& t);
 template <>
 int a(const int& t);
 
+/// template<>
+/// static type<0> d::b<0,int>(int);
 template <>
 type<0> d::b<0, int>(int);
 
+/// template<>
+/// int d::c();
 template <>
 auto d::c() -> int;
 
+/// template<>
+/// d::operator int()const;
 template <>
 d::operator int() const;
 
+/// template<>
+/// d::d(int const&);
 template <>
 d::d(const int&);
 )";

test/cpp_language_linkage.cpp

@@ -13,10 +13,22 @@ using namespace cppast;
 TEST_CASE("cpp_language_linkage")
 {
     auto code = R"(
+/// extern "C" enum a{
+/// };
 extern "C" enum a {};
 
 enum b {};
 
+/// extern "C++"{
+///   enum c{
+///   };
+///
+///   enum d{
+///   };
+///
+///   enum e{
+///   };
+/// }
 extern "C++" // yup
 {
     enum c {};
@@ -41,21 +53,23 @@ enum f {};
     REQUIRE(count == 2u);
 
     // check enums for their correct parent
-    count = test_visit<cpp_enum>(*file, [&](const cpp_enum& e) {
-        if (e.name() == "a")
-            check_parent(e, "\"C\"", "a");
-        else if (e.name() == "b")
-            check_parent(e, "cpp_language_linkage.cpp", "b");
-        else if (e.name() == "c")
-            check_parent(e, "\"C++\"", "c");
-        else if (e.name() == "d")
-            check_parent(e, "\"C++\"", "d");
-        else if (e.name() == "e")
-            check_parent(e, "\"C++\"", "e");
-        else if (e.name() == "f")
-            check_parent(e, "cpp_language_linkage.cpp", "f");
-        else
-            REQUIRE(false);
-    });
+    count = test_visit<cpp_enum>(*file,
+                                 [&](const cpp_enum& e) {
+                                     if (e.name() == "a")
+                                         check_parent(e, "\"C\"", "a");
+                                     else if (e.name() == "b")
+                                         check_parent(e, "cpp_language_linkage.cpp", "b");
+                                     else if (e.name() == "c")
+                                         check_parent(e, "\"C++\"", "c");
+                                     else if (e.name() == "d")
+                                         check_parent(e, "\"C++\"", "d");
+                                     else if (e.name() == "e")
+                                         check_parent(e, "\"C++\"", "e");
+                                     else if (e.name() == "f")
+                                         check_parent(e, "cpp_language_linkage.cpp", "f");
+                                     else
+                                         REQUIRE(false);
+                                 },
+                                 false); // don't check code generation here
     REQUIRE(count == 6u);
 }

test/cpp_member_function.cpp

@@ -14,24 +14,36 @@ TEST_CASE("cpp_member_function")
 // no need to test parameters/return types
 struct foo
 {
+    /// void a();
     void a();
+    /// void b()noexcept;
     void b() noexcept;
 
+    /// void c()const;
     void c() const;
-    auto d() const volatile -> void;
+    /// void d()const volatile noexcept;
+    auto d() const volatile noexcept -> void;
+    /// void e()&;
     void e() &;
+    /// void f()const volatile&&;
     void f() const volatile &&;
 
+    /// virtual void g();
     virtual void g();
+    /// virtual void h()=0;
     virtual void h() = 0;
 
+    /// void i();
     void i() {}
+    /// void j()=delete;
     void j() = delete;
 };
 
 struct bar : foo
 {
+    /// virtual void g() override;
     void g();
+    /// virtual void h() override final;
     virtual auto h() -> void override final;
 };
 )";
@@ -43,7 +55,7 @@ struct bar : foo
         REQUIRE(!func.is_variadic());
         REQUIRE(!func.is_constexpr());
         REQUIRE(equal_types(idx, func.return_type(), *cpp_builtin_type::build(cpp_void)));
-        if (func.name() != "b")
+        if (func.name() != "b" && func.name() != "d")
             REQUIRE(!func.noexcept_condition());
         if (func.name() != "g" && func.name() != "h")
             REQUIRE(!func.virtual_info());
@@ -142,8 +154,11 @@ namespace ns
 // most of it only need to be check in member function
 struct foo
 {
+    /// operator int&();
     operator int&();
+    /// explicit operator bool()const;
     explicit operator bool() const;
+    /// constexpr operator ns::type();
     constexpr operator ns::type();
 };
 )";
@@ -192,8 +207,11 @@ TEST_CASE("cpp_constructor")
 // only test constructor specific stuff
 struct foo
 {
+    /// foo()noexcept=default;
     foo() noexcept = default;
+    /// explicit foo(int);
     explicit foo(int);
+    /// constexpr foo(int,char)=delete;
     constexpr foo(int, char) = delete;
 };
 )";
@@ -240,21 +258,25 @@ TEST_CASE("cpp_destructor")
     auto code = R"(
 struct a
 {
+    /// ~a();
     ~a();
 };
 
 struct b
 {
+    /// ~b()noexcept(false);
     ~b() noexcept(false) {}
 };
 
 struct c
 {
+    /// virtual ~c()=default;
     virtual ~c() = default;
 };
 
 struct d : c
 {
+    /// virtual ~d() override final;
     ~d() final;
 };
 )";

test/cpp_member_variable.cpp

@@ -13,8 +13,11 @@ TEST_CASE("cpp_member_variable")
     auto code = R"(
 struct foo
 {
+    /// int a;
     int a;
+    /// float b=3.14f;
     float b = 3.14f;
+    /// mutable char c;
     mutable char c;
 };
 )";
@@ -59,10 +62,15 @@ TEST_CASE("cpp_bitfield")
     auto code = R"(
 struct foo
 {
+    /// char a:3;
     char a : 3;
+    /// mutable char b:2;
     mutable char b : 2;
+    /// char:0;
     char : 0;
+    /// char c:3;
     char c : 3;
+    /// char:4;
     char : 4;
 };
 )";

test/cpp_namespace.cpp

@@ -11,12 +11,22 @@ using namespace cppast;
 TEST_CASE("cpp_namespace")
 {
     auto code = R"(
+/// namespace a{
+/// }
 namespace a {}
 
+/// inline namespace b{
+/// }
 inline namespace b {}
 
+/// namespace c{
+///   namespace d{
+///   }
+/// }
 namespace c
 {
+    /// namespace d{
+    /// }
     namespace d {}
 }
 )";
@@ -57,18 +67,24 @@ TEST_CASE("cpp_namespace_alias")
 namespace outer {}
 namespace ns {}
 
+/// namespace a=outer;
 namespace a = outer;
+/// namespace b=ns;
 namespace b = ns;
 
 namespace outer
 {
     namespace ns {}
 
+    /// namespace c=ns;
     namespace c = ns;
+    /// namespace d=::outer;
     namespace d = ::outer;
 }
 
+/// namespace e=outer::ns;
 namespace e = outer::ns;
+/// namespace f=outer::c;
 namespace f = outer::c;
 )";
 
@@ -117,17 +133,22 @@ TEST_CASE("cpp_using_directive")
 namespace ns1 {}
 namespace ns2 {}
 
+/// using namespace ns1;
 using namespace ns1;
+/// using namespace ns2;
 using namespace ns2;
 
 namespace outer
 {
     namespace ns {}
 
+    /// using namespace ns;
     using namespace ns;
+    /// using namespace ::ns1;
     using namespace ::ns1;
 }
 
+/// using namespace outer::ns;
 using namespace outer::ns;
 )";
 
@@ -180,7 +201,9 @@ namespace ns2
     enum b {};
 }
 
+/// using ns1::a;
 using ns1::a;
+/// using ns2::b;
 using ns2::b;
 
 namespace outer
@@ -190,10 +213,13 @@ namespace outer
         enum c {};
     }
 
+    /// using ns::c;
     using ns::c;
 }
 
+/// using outer::ns::c;
 using outer::ns::c;
+/// using outer::c;
 using outer::c;
 
 namespace ns1
@@ -202,6 +228,7 @@ namespace ns1
     void d(float);
 }
 
+/// using ns1::d;
 using ns1::d;
 )";
 

test/cpp_preprocessor.cpp

@@ -13,15 +13,21 @@ TEST_CASE("cpp_macro_definition")
     auto        code    = R"(
 #include <iostream>
 #define G
+/// #define A
 #define A
+/// #define B hello
 #define B hello
 namespace ns {}
+/// #define C(x,y) x##_name
 #define C(x, y) x##_name
+/// #define D(...) __VA_ARGS__
 #define D(...) __VA_ARGS__
+/// #define E() barbaz
 #define E() bar\
 baz
 namespace ns2
 {
+/// #define F () bar
 #define F () bar
 #undef G
 }

test/cpp_template_parameter.cpp

@@ -35,60 +35,82 @@ using e = void;
 
     cpp_entity_index idx;
     auto             file = parse(idx, "cpp_template_type_parameter.cpp", code);
-    auto count = test_visit<cpp_alias_template>(*file, [&](const cpp_alias_template& alias) {
-        REQUIRE(equal_types(idx, alias.type_alias().underlying_type(),
-                            *cpp_builtin_type::build(cpp_void)));
+    auto             count =
+        test_visit<cpp_alias_template>(*file,
+                                       [&](const cpp_alias_template& alias) {
+                                           REQUIRE(equal_types(idx,
+                                                               alias.type_alias().underlying_type(),
+                                                               *cpp_builtin_type::build(cpp_void)));
 
-        for (auto& p : alias.parameters())
-        {
-            REQUIRE(p.kind() == cpp_entity_kind::template_type_parameter_t);
+                                           for (auto& p : alias.parameters())
+                                           {
+                                               REQUIRE(
+                                                   p.kind()
+                                                   == cpp_entity_kind::template_type_parameter_t);
 
-            auto& param = static_cast<const cpp_template_type_parameter&>(p);
-            if (param.name() == "A")
-            {
-                REQUIRE(alias.name() == "a");
-                REQUIRE(param.keyword() == cpp_template_keyword::keyword_typename);
-                REQUIRE(!param.is_variadic());
-                REQUIRE(!param.default_type());
-            }
-            else if (param.name() == "B")
-            {
-                REQUIRE(alias.name() == "b");
-                REQUIRE(param.keyword() == cpp_template_keyword::keyword_class);
-                REQUIRE(param.is_variadic());
-                REQUIRE(!param.default_type());
-            }
-            else if (param.name() == "")
-            {
-                REQUIRE(alias.name() == "c");
-                REQUIRE(param.keyword() == cpp_template_keyword::keyword_typename);
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_type().has_value());
-                REQUIRE(equal_types(idx, param.default_type().value(),
-                                    *cpp_unexposed_type::build("const int*")));
-            }
-            else if (param.name() == "D")
-            {
-                REQUIRE(alias.name() == "d");
-                REQUIRE(param.keyword() == cpp_template_keyword::keyword_class);
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_type().has_value());
-                REQUIRE(equal_types(idx, param.default_type().value(),
-                                    *cpp_unexposed_type::build("decltype(1+3)")));
-            }
-            else if (param.name() == "E")
-            {
-                REQUIRE(alias.name() == "e");
-                REQUIRE(param.keyword() == cpp_template_keyword::keyword_typename);
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_type().has_value());
-                REQUIRE(equal_types(idx, param.default_type().value(),
-                                    *cpp_unexposed_type::build("a<void>")));
-            }
-            else
-                REQUIRE(false);
-        }
-    });
+                                               auto& param =
+                                                   static_cast<const cpp_template_type_parameter&>(
+                                                       p);
+                                               if (param.name() == "A")
+                                               {
+                                                   REQUIRE(alias.name() == "a");
+                                                   REQUIRE(
+                                                       param.keyword()
+                                                       == cpp_template_keyword::keyword_typename);
+                                                   REQUIRE(!param.is_variadic());
+                                                   REQUIRE(!param.default_type());
+                                               }
+                                               else if (param.name() == "B")
+                                               {
+                                                   REQUIRE(alias.name() == "b");
+                                                   REQUIRE(param.keyword()
+                                                           == cpp_template_keyword::keyword_class);
+                                                   REQUIRE(param.is_variadic());
+                                                   REQUIRE(!param.default_type());
+                                               }
+                                               else if (param.name() == "")
+                                               {
+                                                   REQUIRE(alias.name() == "c");
+                                                   REQUIRE(
+                                                       param.keyword()
+                                                       == cpp_template_keyword::keyword_typename);
+                                                   REQUIRE(!param.is_variadic());
+                                                   REQUIRE(param.default_type().has_value());
+                                                   REQUIRE(equal_types(idx,
+                                                                       param.default_type().value(),
+                                                                       *cpp_unexposed_type::build(
+                                                                           "const int*")));
+                                               }
+                                               else if (param.name() == "D")
+                                               {
+                                                   REQUIRE(alias.name() == "d");
+                                                   REQUIRE(param.keyword()
+                                                           == cpp_template_keyword::keyword_class);
+                                                   REQUIRE(!param.is_variadic());
+                                                   REQUIRE(param.default_type().has_value());
+                                                   REQUIRE(equal_types(idx,
+                                                                       param.default_type().value(),
+                                                                       *cpp_unexposed_type::build(
+                                                                           "decltype(1+3)")));
+                                               }
+                                               else if (param.name() == "E")
+                                               {
+                                                   REQUIRE(alias.name() == "e");
+                                                   REQUIRE(
+                                                       param.keyword()
+                                                       == cpp_template_keyword::keyword_typename);
+                                                   REQUIRE(!param.is_variadic());
+                                                   REQUIRE(param.default_type().has_value());
+                                                   REQUIRE(equal_types(idx,
+                                                                       param.default_type().value(),
+                                                                       *cpp_unexposed_type::build(
+                                                                           "a<void>")));
+                                               }
+                                               else
+                                                   REQUIRE(false);
+                                           }
+                                       },
+                                       false); // can't check synopsis with comments
     REQUIRE(count == 5u);
 }
 
@@ -109,57 +131,62 @@ using d = void;
 )";
 
     cpp_entity_index idx;
-    auto             file = parse(idx, "cpp_non_type_template_parameter.cpp", code);
-    auto count = test_visit<cpp_alias_template>(*file, [&](const cpp_alias_template& alias) {
-        REQUIRE(equal_types(idx, alias.type_alias().underlying_type(),
-                            *cpp_builtin_type::build(cpp_void)));
+    auto             file  = parse(idx, "cpp_non_type_template_parameter.cpp", code);
+    auto             count = test_visit<cpp_alias_template>(
+        *file,
+        [&](const cpp_alias_template& alias) {
+            REQUIRE(equal_types(idx, alias.type_alias().underlying_type(),
+                                *cpp_builtin_type::build(cpp_void)));
 
-        for (auto& p : alias.parameters())
-        {
-            REQUIRE(p.kind() == cpp_entity_kind::non_type_template_parameter_t);
+            for (auto& p : alias.parameters())
+            {
+                REQUIRE(p.kind() == cpp_entity_kind::non_type_template_parameter_t);
 
-            auto& param = static_cast<const cpp_non_type_template_parameter&>(p);
-            if (param.name() == "A")
-            {
-                REQUIRE(alias.name() == "a");
-                REQUIRE(equal_types(idx, param.type(), *cpp_builtin_type::build(cpp_int)));
-                REQUIRE(!param.is_variadic());
-                REQUIRE(!param.default_value());
-            }
-            else if (param.name() == "")
-            {
-                REQUIRE(alias.name() == "b");
-                REQUIRE(equal_types(idx, param.type(),
-                                    *cpp_pointer_type::build(cpp_builtin_type::build(cpp_char))));
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_value());
-                REQUIRE(equal_expressions(param.default_value().value(),
+                auto& param = static_cast<const cpp_non_type_template_parameter&>(p);
+                if (param.name() == "A")
+                {
+                    REQUIRE(alias.name() == "a");
+                    REQUIRE(equal_types(idx, param.type(), *cpp_builtin_type::build(cpp_int)));
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(!param.default_value());
+                }
+                else if (param.name() == "")
+                {
+                    REQUIRE(alias.name() == "b");
+                    REQUIRE(equal_types(idx, param.type(), *cpp_pointer_type::build(
+                                                               cpp_builtin_type::build(cpp_char))));
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(param.default_value());
+                    REQUIRE(
+                        equal_expressions(param.default_value().value(),
                                           *cpp_literal_expression::build(cpp_builtin_type::build(
                                                                              cpp_nullptr),
                                                                          "nullptr")));
-            }
-            else if (param.name() == "C")
-            {
-                REQUIRE(alias.name() == "c");
-                REQUIRE(equal_types(idx, param.type(), *cpp_builtin_type::build(cpp_int)));
-                REQUIRE(param.is_variadic());
-                REQUIRE(!param.default_value());
-            }
-            else if (param.name() == "D")
-            {
-                REQUIRE(alias.name() == "d");
+                }
+                else if (param.name() == "C")
+                {
+                    REQUIRE(alias.name() == "c");
+                    REQUIRE(equal_types(idx, param.type(), *cpp_builtin_type::build(cpp_int)));
+                    REQUIRE(param.is_variadic());
+                    REQUIRE(!param.default_value());
+                }
+                else if (param.name() == "D")
+                {
+                    REQUIRE(alias.name() == "d");
 
-                cpp_function_type::builder builder(cpp_builtin_type::build(cpp_void));
-                builder.is_variadic();
-                REQUIRE(equal_types(idx, param.type(), *cpp_pointer_type::build(builder.finish())));
+                    cpp_function_type::builder builder(cpp_builtin_type::build(cpp_void));
+                    builder.is_variadic();
+                    REQUIRE(
+                        equal_types(idx, param.type(), *cpp_pointer_type::build(builder.finish())));
 
-                REQUIRE(!param.is_variadic());
-                REQUIRE(!param.default_value());
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(!param.default_value());
+                }
+                else
+                    REQUIRE(false);
             }
-            else
-                REQUIRE(false);
-        }
-    });
+        },
+        false); // can't check synopsis with comments
     REQUIRE(count == 4u);
 }
 
@@ -187,105 +214,108 @@ using d = void;
 )";
 
     cpp_entity_index idx;
-    auto             file = parse(idx, "cpp_template_template_parameter.cpp", code);
-    auto count = test_visit<cpp_alias_template>(*file, [&](const cpp_alias_template& alias) {
-        REQUIRE(equal_types(idx, alias.type_alias().underlying_type(),
-                            *cpp_builtin_type::build(cpp_void)));
-        if (alias.name() == "def")
-            return;
+    auto             file  = parse(idx, "cpp_template_template_parameter.cpp", code);
+    auto             count = test_visit<cpp_alias_template>(
+        *file,
+        [&](const cpp_alias_template& alias) {
+            REQUIRE(equal_types(idx, alias.type_alias().underlying_type(),
+                                *cpp_builtin_type::build(cpp_void)));
+            if (alias.name() == "def")
+                return;
 
-        for (auto& p : alias.parameters())
-        {
-            REQUIRE(p.kind() == cpp_entity_kind::template_template_parameter_t);
-
-            auto& param = static_cast<const cpp_template_template_parameter&>(p);
-            REQUIRE(param.keyword() == cpp_template_keyword::keyword_class);
-            if (param.name() == "A")
+            for (auto& p : alias.parameters())
             {
-                REQUIRE(alias.name() == "a");
-                REQUIRE(!param.is_variadic());
-                REQUIRE(!param.default_template());
+                REQUIRE(p.kind() == cpp_entity_kind::template_template_parameter_t);
 
-                auto no = 0u;
-                for (auto& p_param : param)
+                auto& param = static_cast<const cpp_template_template_parameter&>(p);
+                REQUIRE(param.keyword() == cpp_template_keyword::keyword_class);
+                if (param.name() == "A")
                 {
-                    ++no;
-                    REQUIRE(p_param.name() == "T");
-                    REQUIRE(p_param.kind() == cpp_entity_kind::template_type_parameter_t);
-                }
-                REQUIRE(no == 1u);
-            }
-            else if (param.name() == "B")
-            {
-                REQUIRE(alias.name() == "b");
-                REQUIRE(param.is_variadic());
-                REQUIRE(!param.default_template());
+                    REQUIRE(alias.name() == "a");
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(!param.default_template());
 
-                auto cur = param.begin();
-                REQUIRE(cur != param.end());
-                REQUIRE(cur->name().empty());
-                REQUIRE(cur->kind() == cpp_entity_kind::non_type_template_parameter_t);
-
-                ++cur;
-                REQUIRE(cur != param.end());
-                REQUIRE(cur->name().empty());
-                REQUIRE(cur->kind() == cpp_entity_kind::template_type_parameter_t);
-
-                ++cur;
-                REQUIRE(cur == param.end());
-            }
-            else if (param.name() == "C")
-            {
-                REQUIRE(alias.name() == "c");
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_template());
-
-                auto def = param.default_template().value();
-                REQUIRE(def.name() == "ns::def");
-                auto entities = def.get(idx);
-                REQUIRE(entities.size() == 1u);
-                REQUIRE(entities[0]->name() == "def");
-
-                auto no = 0u;
-                for (auto& p_param : param)
-                {
-                    ++no;
-                    REQUIRE(p_param.name() == "");
-                    REQUIRE(p_param.kind() == cpp_entity_kind::non_type_template_parameter_t);
-                }
-                REQUIRE(no == 1u);
-            }
-            else if (param.name() == "D")
-            {
-                REQUIRE(alias.name() == "d");
-                REQUIRE(!param.is_variadic());
-                REQUIRE(param.default_template());
-
-                auto def = param.default_template().value();
-                REQUIRE(def.name() == "a");
-                auto entities = def.get(idx);
-                REQUIRE(entities.size() == 1u);
-                REQUIRE(entities[0]->name() == "a");
-
-                auto no = 0u;
-                for (auto& p_param : param)
-                {
-                    ++no;
-                    REQUIRE(p_param.name() == "");
-                    REQUIRE(p_param.kind() == cpp_entity_kind::template_template_parameter_t);
-                    for (auto& p_p_param :
-                         static_cast<const cpp_template_template_parameter&>(p_param))
+                    auto no = 0u;
+                    for (auto& p_param : param)
                     {
                         ++no;
-                        REQUIRE(p_p_param.name() == "");
-                        REQUIRE(p_p_param.kind() == cpp_entity_kind::template_type_parameter_t);
+                        REQUIRE(p_param.name() == "T");
+                        REQUIRE(p_param.kind() == cpp_entity_kind::template_type_parameter_t);
                     }
+                    REQUIRE(no == 1u);
                 }
-                REQUIRE(no == 2u);
+                else if (param.name() == "B")
+                {
+                    REQUIRE(alias.name() == "b");
+                    REQUIRE(param.is_variadic());
+                    REQUIRE(!param.default_template());
+
+                    auto cur = param.begin();
+                    REQUIRE(cur != param.end());
+                    REQUIRE(cur->name().empty());
+                    REQUIRE(cur->kind() == cpp_entity_kind::non_type_template_parameter_t);
+
+                    ++cur;
+                    REQUIRE(cur != param.end());
+                    REQUIRE(cur->name().empty());
+                    REQUIRE(cur->kind() == cpp_entity_kind::template_type_parameter_t);
+
+                    ++cur;
+                    REQUIRE(cur == param.end());
+                }
+                else if (param.name() == "C")
+                {
+                    REQUIRE(alias.name() == "c");
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(param.default_template());
+
+                    auto def = param.default_template().value();
+                    REQUIRE(def.name() == "ns::def");
+                    auto entities = def.get(idx);
+                    REQUIRE(entities.size() == 1u);
+                    REQUIRE(entities[0]->name() == "def");
+
+                    auto no = 0u;
+                    for (auto& p_param : param)
+                    {
+                        ++no;
+                        REQUIRE(p_param.name() == "");
+                        REQUIRE(p_param.kind() == cpp_entity_kind::non_type_template_parameter_t);
+                    }
+                    REQUIRE(no == 1u);
+                }
+                else if (param.name() == "D")
+                {
+                    REQUIRE(alias.name() == "d");
+                    REQUIRE(!param.is_variadic());
+                    REQUIRE(param.default_template());
+
+                    auto def = param.default_template().value();
+                    REQUIRE(def.name() == "a");
+                    auto entities = def.get(idx);
+                    REQUIRE(entities.size() == 1u);
+                    REQUIRE(entities[0]->name() == "a");
+
+                    auto no = 0u;
+                    for (auto& p_param : param)
+                    {
+                        ++no;
+                        REQUIRE(p_param.name() == "");
+                        REQUIRE(p_param.kind() == cpp_entity_kind::template_template_parameter_t);
+                        for (auto& p_p_param :
+                             static_cast<const cpp_template_template_parameter&>(p_param))
+                        {
+                            ++no;
+                            REQUIRE(p_p_param.name() == "");
+                            REQUIRE(p_p_param.kind() == cpp_entity_kind::template_type_parameter_t);
+                        }
+                    }
+                    REQUIRE(no == 2u);
+                }
+                else
+                    REQUIRE(false);
             }
-            else
-                REQUIRE(false);
-        }
-    });
+        },
+        false); // can't check synopsis with comments
     REQUIRE(count == 5u);
 }

test/cpp_type_alias.cpp

@@ -21,26 +21,26 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
 
     switch (parsed.kind())
     {
-    case cpp_type_kind::builtin:
+    case cpp_type_kind::builtin_t:
         return static_cast<const cpp_builtin_type&>(parsed).builtin_type_kind()
                == static_cast<const cpp_builtin_type&>(synthesized).builtin_type_kind();
 
-    case cpp_type_kind::user_defined:
+    case cpp_type_kind::user_defined_t:
     {
         auto& user_parsed      = static_cast<const cpp_user_defined_type&>(parsed);
         auto& user_synthesized = static_cast<const cpp_user_defined_type&>(synthesized);
         return equal_ref(idx, user_parsed.entity(), user_synthesized.entity());
     }
 
-    case cpp_type_kind::auto_:
+    case cpp_type_kind::auto_t:
         return true;
-    case cpp_type_kind::decltype_:
+    case cpp_type_kind::decltype_t:
         return equal_expressions(static_cast<const cpp_decltype_type&>(parsed).expression(),
                                  static_cast<const cpp_decltype_type&>(synthesized).expression());
-    case cpp_type_kind::decltype_auto:
+    case cpp_type_kind::decltype_auto_t:
         return true;
 
-    case cpp_type_kind::cv_qualified:
+    case cpp_type_kind::cv_qualified_t:
     {
         auto& cv_a = static_cast<const cpp_cv_qualified_type&>(parsed);
         auto& cv_b = static_cast<const cpp_cv_qualified_type&>(synthesized);
@@ -48,10 +48,10 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
                && equal_types(idx, cv_a.type(), cv_b.type());
     }
 
-    case cpp_type_kind::pointer:
+    case cpp_type_kind::pointer_t:
         return equal_types(idx, static_cast<const cpp_pointer_type&>(parsed).pointee(),
                            static_cast<const cpp_pointer_type&>(synthesized).pointee());
-    case cpp_type_kind::reference:
+    case cpp_type_kind::reference_t:
     {
         auto& ref_a = static_cast<const cpp_reference_type&>(parsed);
         auto& ref_b = static_cast<const cpp_reference_type&>(synthesized);
@@ -59,7 +59,7 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
                && equal_types(idx, ref_a.referee(), ref_b.referee());
     }
 
-    case cpp_type_kind::array:
+    case cpp_type_kind::array_t:
     {
         auto& array_a = static_cast<const cpp_array_type&>(parsed);
         auto& array_b = static_cast<const cpp_array_type&>(synthesized);
@@ -77,7 +77,7 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
         return equal_expressions(size_a, size_b);
     }
 
-    case cpp_type_kind::function:
+    case cpp_type_kind::function_t:
     {
         auto& func_a = static_cast<const cpp_function_type&>(parsed);
         auto& func_b = static_cast<const cpp_function_type&>(synthesized);
@@ -98,7 +98,7 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
         }
         return iter_a == func_a.parameter_types().end() && iter_b == func_b.parameter_types().end();
     }
-    case cpp_type_kind::member_function:
+    case cpp_type_kind::member_function_t:
     {
         auto& func_a = static_cast<const cpp_member_function_type&>(parsed);
         auto& func_b = static_cast<const cpp_member_function_type&>(synthesized);
@@ -121,7 +121,7 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
         }
         return iter_a == func_a.parameter_types().end() && iter_b == func_b.parameter_types().end();
     }
-    case cpp_type_kind::member_object:
+    case cpp_type_kind::member_object_t:
     {
         auto& obj_a = static_cast<const cpp_member_object_type&>(parsed);
         auto& obj_b = static_cast<const cpp_member_object_type&>(synthesized);
@@ -131,14 +131,14 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
         return equal_types(idx, obj_a.object_type(), obj_b.object_type());
     }
 
-    case cpp_type_kind::template_parameter:
+    case cpp_type_kind::template_parameter_t:
     {
         auto& entity_parsed = static_cast<const cpp_template_parameter_type&>(parsed).entity();
         auto& entity_synthesized =
             static_cast<const cpp_template_parameter_type&>(synthesized).entity();
         return equal_ref(idx, entity_parsed, entity_synthesized);
     }
-    case cpp_type_kind::template_instantiation:
+    case cpp_type_kind::template_instantiation_t:
     {
         auto& inst_parsed      = static_cast<const cpp_template_instantiation_type&>(parsed);
         auto& inst_synthesized = static_cast<const cpp_template_instantiation_type&>(synthesized);
@@ -179,10 +179,10 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
                && iter_b == inst_synthesized.arguments().end();
     }
     // TODO: implement equality when those can be parsed
-    case cpp_type_kind::dependent:
+    case cpp_type_kind::dependent_t:
         break;
 
-    case cpp_type_kind::unexposed:
+    case cpp_type_kind::unexposed_t:
         return static_cast<const cpp_unexposed_type&>(parsed).name()
                == static_cast<const cpp_unexposed_type&>(synthesized).name();
     }
@@ -194,45 +194,66 @@ bool equal_types(const cpp_entity_index& idx, const cpp_type& parsed, const cpp_
 // other test cases don't need that anymore
 TEST_CASE("cpp_type_alias")
 {
-    const char* code = nullptr;
+    const char* code       = nullptr;
+    auto        check_code = false;
     SECTION("using")
     {
-        code = R"(
+        check_code = true;
+        code       = R"(
 // basic
+/// using a=int;
 using a = int;
+/// using b=long double const volatile;
 using b = const long double volatile;
 
 // pointers
+/// using c=int*;
 using c = int*;
+/// using d=unsigned int const*;
 using d = const unsigned int*;
+/// using e=unsigned int const* volatile;
 using e = unsigned const * volatile;
 
 // references
+/// using f=int&;
 using f = int&;
+/// using g=int const&&;
 using g = const int&&;
 
 // user-defined types
+/// using h=c;
 using h = c;
+/// using i=d const;
 using i = const d;
+/// using j=e*;
 using j = e*;
 
 // arrays
+/// using k=int[42];
 using k = int[42];
+/// using l=float*[];
 using l = float*[];
+/// using m=char[42];
 using m = char[3 * 2 + 4 ? 42 : 43];
 
 // function pointers
+/// using n=void(*)(int);
 using n = void(*)(int);
+/// using o=char*(&)(int const&,...);
 using o = char*(&)(const int&,...);
+/// using p=n(*)(int,o);
 using p = n(*)(int, o);
 
 struct foo {};
 
 // member function pointers
+/// using q=void(foo::*)(int);
 using q = void(foo::*)(int);
+/// using r=void(foo::*)(int,...)const&;
 using r = void(foo::*)(int,...) const &;
 
 // member data pointers
+/// using s=int(foo::*);
 using s = int(foo::*);
 
 // user-defined types inline definition
@@ -241,12 +262,14 @@ using u = const struct u_ {}*;
 using v = struct {};
 
 // decltype
+/// using w=decltype(0);
 using w = decltype(0);
 )";
     }
     SECTION("typedef")
     {
-        code = R"(
+        check_code = false; // will always generate using
+        code       = R"(
 // basic
 typedef int a;
 typedef const long double volatile b;
@@ -455,6 +478,8 @@ typedef decltype(0) w;
         {
             auto type = cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "t_"));
             REQUIRE(equal_types(idx, alias.underlying_type(), *type));
+            return false; // inhibit comment check for next three entities
+            // as they can't be documented (will always apply to the inline type)
         }
         else if (alias.name() == "u")
         {
@@ -462,11 +487,13 @@ typedef decltype(0) w;
                 add_cv(cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "u_")),
                        cpp_cv_const));
             REQUIRE(equal_types(idx, alias.underlying_type(), *type));
+            return false;
         }
         else if (alias.name() == "v")
         {
             auto type = cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "v"));
             REQUIRE(equal_types(idx, alias.underlying_type(), *type));
+            return false;
         }
         else if (alias.name() == "w")
         {
@@ -476,6 +503,8 @@ typedef decltype(0) w;
         }
         else
             REQUIRE(false);
+
+        return check_code;
     });
     REQUIRE(count == 23u);
 }

test/cpp_variable.cpp

@@ -14,17 +14,25 @@ TEST_CASE("cpp_variable")
 {
     auto code = R"(
 // basic
+/// int a;
 int a;
+/// unsigned long long b=42;
 unsigned long long b = 42;
+/// float c=3.f+0.14f;
 float c = 3.f + 0.14f;
 
 // with storage class specifiers
+/// extern int d;
 extern int d; // actually declaration
+/// static int e;
 static int e;
+/// thread_local int f;
 thread_local int f;
+/// static thread_local int g;
 thread_local static int g;
 
 // constexpr
+/// constexpr int const h=12;
 constexpr int h = 12;
 
 // inline definition
@@ -34,11 +42,15 @@ struct baz {} k{};
 static struct {} l;
 
 // auto
+/// auto m=128;
 auto m = 128;
+/// auto const& n=m;
 const auto& n = m;
 
 // decltype
+/// decltype(0) o;
 decltype(0) o;
+/// decltype(o) const& p=o;
 const decltype(o)& p = o;
 )";
 
@@ -106,10 +118,14 @@ const decltype(o)& p = o;
                                                               "12")),
                            cpp_storage_class_none, true, false);
         else if (var.name() == "i")
+        {
             check_variable(var,
                            *cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "foo")),
                            nullptr, cpp_storage_class_none, false, false);
+            return false; // can't check code here
+        }
         else if (var.name() == "j")
+        {
             check_variable(var, *cpp_cv_qualified_type::build(cpp_user_defined_type::build(
                                                                   cpp_type_ref(cpp_entity_id(""),
                                                                                "bar")),
@@ -120,7 +136,10 @@ const decltype(o)& p = o;
                                                                                  "bar")),
                                                                 "bar()")),
                            cpp_storage_class_none, false, false);
+            return false;
+        }
         else if (var.name() == "k")
+        {
             check_variable(var,
                            *cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "baz")),
                            type_safe::ref(
@@ -129,9 +148,14 @@ const decltype(o)& p = o;
                                                                                  "baz")),
                                                                 "{}")),
                            cpp_storage_class_none, false, false);
+            return false;
+        }
         else if (var.name() == "l")
+        {
             check_variable(var, *cpp_user_defined_type::build(cpp_type_ref(cpp_entity_id(""), "")),
                            nullptr, cpp_storage_class_static, false, false);
+            return false;
+        }
         else if (var.name() == "m")
             check_variable(var, *cpp_auto_type::build(),
                            type_safe::ref(
@@ -167,6 +191,8 @@ const decltype(o)& p = o;
                            cpp_storage_class_none, false, false);
         else
             REQUIRE(false);
+
+        return true;
     });
     REQUIRE(count == 16u);
 }
@@ -176,8 +202,11 @@ TEST_CASE("static cpp_variable")
     auto code = R"(
 struct test
 {
+    /// static int a;
     static int a;
+    /// static int const b;
     static const int b;
+    /// static thread_local int c;
     static thread_local int c;
 };
 )";

test/test_parser.hpp

@@ -9,6 +9,7 @@
 
 #include <catch.hpp>
 
+#include <cppast/code_generator.hpp>
 #include <cppast/cpp_entity_kind.hpp>
 #include <cppast/cpp_expression.hpp>
 #include <cppast/cpp_type.hpp>
@@ -39,8 +40,72 @@ inline std::unique_ptr<cppast::cpp_file> parse(const cppast::cpp_entity_index& i
     return result;
 }
 
+class test_generator : public cppast::code_generator
+{
+public:
+    const std::string& str() const noexcept
+    {
+        return str_;
+    }
+
+private:
+    void do_indent() override
+    {
+        ++indent_;
+    }
+
+    void do_unindent() override
+    {
+        if (indent_)
+            --indent_;
+    }
+
+    void do_write_token_seq(cppast::string_view tokens)
+    {
+        if (was_newline_)
+        {
+            str_ += std::string(indent_ * 2u, ' ');
+            was_newline_ = false;
+        }
+        str_ += tokens.c_str();
+    }
+
+    void do_write_newline() override
+    {
+        str_ += "\n";
+        was_newline_ = true;
+    }
+
+    std::string str_;
+    unsigned    indent_      = 0;
+    bool        was_newline_ = false;
+};
+
+inline std::string get_code(const cppast::cpp_entity& e)
+{
+    test_generator generator;
+    cppast::generate_code(generator, e);
+    auto str = generator.str();
+    if (!str.empty() && str.back() == '\n')
+        str.pop_back();
+    return str;
+}
+
+template <typename Func, typename T>
+auto visit_callback(bool, Func f, const T& t) -> decltype(f(t) == true)
+{
+    return f(t);
+}
+
+template <typename Func, typename T>
+bool visit_callback(int check, Func f, const T& t)
+{
+    f(t);
+    return check == 1;
+}
+
 template <typename T, typename Func>
-unsigned test_visit(const cppast::cpp_file& file, Func f)
+unsigned test_visit(const cppast::cpp_file& file, Func f, bool check_code = true)
 {
     auto count = 0u;
     cppast::visit(file, [&](const cppast::cpp_entity& e, cppast::visitor_info info) {
@@ -49,9 +114,16 @@ unsigned test_visit(const cppast::cpp_file& file, Func f)
 
         if (e.kind() == T::kind())
         {
-            auto& obj = static_cast<const T&>(e);
-            f(obj);
+            auto& obj       = static_cast<const T&>(e);
+            auto  check_cur = visit_callback(check_code, f, obj);
             ++count;
+
+            if (check_cur)
+            {
+                INFO(e.name());
+                REQUIRE(e.comment());
+                REQUIRE(e.comment().value() == get_code(e));
+            }
         }
 
         return true;
@@ -88,11 +160,11 @@ inline bool equal_expressions(const cppast::cpp_expression& parsed,
         return false;
     switch (parsed.kind())
     {
-    case cpp_expression_kind::unexposed:
+    case cpp_expression_kind::unexposed_t:
         return static_cast<const cpp_unexposed_expression&>(parsed).expression()
                == static_cast<const cpp_unexposed_expression&>(synthesized).expression();
 
-    case cpp_expression_kind::literal:
+    case cpp_expression_kind::literal_t:
         return static_cast<const cpp_literal_expression&>(parsed).value()
                == static_cast<const cpp_literal_expression&>(synthesized).value();
     }