From bb3253220bec0aeb30562822ec260bb1c2e6223a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonathan=20M=C3=BCller?= <git@foonathan.net>
Date: Sat, 27 May 2017 11:11:54 +0200
Subject: [PATCH 1/2] Add formatting options to code generation

---
 include/cppast/code_generator.hpp |  53 ++++++++++--
 src/code_generator.cpp            | 133 ++++++++++++++++++------------
 src/cpp_type.cpp                  |  73 +++++++++++-----
 test/code_generator.cpp           |  67 +++++++++++++--
 4 files changed, 238 insertions(+), 88 deletions(-)

diff --git a/include/cppast/code_generator.hpp b/include/cppast/code_generator.hpp
index d0cd653..a224119 100644
--- a/include/cppast/code_generator.hpp
+++ b/include/cppast/code_generator.hpp
@@ -119,6 +119,27 @@ namespace cppast
     {
     } whitespace{};
 
+    /// Flags that control the code formatting.
+    ///
+    /// If a flag is set, it adds additional whitespace.
+    /// If no flags are set, it will only add the whitespace necessary to separate tokens.
+    enum class formatting_flags
+    {
+        brace_nl, //< Set to put the opening braces on a new line.
+        brace_ws, //< Set to put the opening brace at the end of the line after whitespace.
+
+        ptr_ref_var, //< Set to put pointers and references at the variable name (default is type).
+
+        comma_ws,    //< Set to put whitespace after a comma.
+        bracket_ws,  //< Set to put whitespace inside brackets.
+        operator_ws, //< Set to put whitespace around operators.
+
+        _flag_set_size, //< \exclude
+    };
+
+    /// A set of formatting flags.
+    using formatting = type_safe::flag_set<formatting_flags>;
+
     /// Base class to control the code generation.
     ///
     /// Inherit from it to customize how a [cppast::cpp_entity]() is printed
@@ -127,8 +148,10 @@ namespace cppast
     {
     public:
         code_generator(const code_generator&) = delete;
+
         code_generator& operator=(const code_generator&) = delete;
-        virtual ~code_generator() noexcept               = default;
+
+        virtual ~code_generator() noexcept = default;
 
         /// Flags that control the generation.
         enum generation_flags
@@ -178,6 +201,7 @@ namespace cppast
             }
 
             output(const output&) = delete;
+
             output& operator=(const output&) = delete;
 
             /// \returns Whether or not the `on_XXX` function returned something other than `exclude`.
@@ -189,17 +213,23 @@ namespace cppast
             }
 
             /// \returns The generation options.
-            generation_options options() const noexcept
+            generation_options options() const
             {
                 return options_;
             }
 
             /// \returns The generation options for the given entity.
-            generation_options options(const cpp_entity& e) const noexcept
+            generation_options options(const cpp_entity& e) const
             {
                 return gen_->do_get_options(e);
             }
 
+            /// \returns The formatting.
+            cppast::formatting formatting() const
+            {
+                return gen_->do_get_formatting();
+            }
+
             /// \returns Whether or not the definition should be generated as well.
             bool generate_definition() const noexcept
             {
@@ -230,6 +260,13 @@ namespace cppast
                     gen_->do_unindent();
             }
 
+            /// \effects Calls `func(*this)`.
+            const output& operator<<(void (*func)(const output&)) const
+            {
+                func(*this);
+                return *this;
+            }
+
             /// \effects Calls `do_write_keyword()`.
             const output& operator<<(const keyword& k) const
             {
@@ -337,6 +374,13 @@ namespace cppast
         code_generator() noexcept = default;
 
     private:
+        /// \returns The formatting options that should be used.
+        /// The base class version has no flags set.
+        virtual formatting do_get_formatting() const
+        {
+            return {};
+        }
+
         /// \returns The generation options for that entity.
         /// The base class version always returns no special options.
         virtual generation_options do_get_options(const cpp_entity& e)
@@ -451,9 +495,6 @@ namespace cppast
     /// 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.
     ///
     /// \returns Whether or not any code was actually written.
     bool generate_code(code_generator& generator, const cpp_entity& e);
diff --git a/src/code_generator.cpp b/src/code_generator.cpp
index 17fd928..8945cb5 100644
--- a/src/code_generator.cpp
+++ b/src/code_generator.cpp
@@ -28,16 +28,32 @@ using namespace cppast;
 
 namespace
 {
-    template <typename Sep>
-    auto write_sep(code_generator::output& output, Sep s) -> decltype(output << s)
+    void opening_brace(const code_generator::output& output)
     {
-        return output << s;
+        if (output.formatting().is_set(formatting_flags::brace_nl))
+            output << newl;
+        else if (output.formatting().is_set(formatting_flags::brace_ws))
+            output << whitespace;
+        output << punctuation("{");
     }
 
-    template <typename Sep>
-    auto write_sep(code_generator::output& output, Sep s) -> decltype(s(output))
+    void comma(const code_generator::output& output)
     {
-        return s(output);
+        output << punctuation(",");
+        if (output.formatting().is_set(formatting_flags::comma_ws))
+            output << whitespace;
+    }
+
+    void bracket_ws(const code_generator::output& output)
+    {
+        if (output.formatting().is_set(formatting_flags::bracket_ws))
+            output << whitespace;
+    }
+
+    void operator_ws(const code_generator::output& output)
+    {
+        if (output.formatting().is_set(formatting_flags::operator_ws))
+            output << whitespace;
     }
 
     template <class Container, typename Sep>
@@ -47,7 +63,7 @@ namespace
         for (auto& child : cont)
         {
             if (need_sep)
-                write_sep(output, s);
+                output << s;
             need_sep = generate_code(*output.generator(), child);
         }
         return need_sep;
@@ -73,7 +89,8 @@ namespace
         {
             output << preprocessor_token("#define") << whitespace << identifier(def.name());
             if (def.is_function_like())
-                output << preprocessor_token("(") << preprocessor_token(def.parameters().value())
+                output << preprocessor_token("(") << bracket_ws
+                       << preprocessor_token(def.parameters().value()) << bracket_ws
                        << preprocessor_token(")");
             if (!def.replacement().empty())
                 output << whitespace << preprocessor_token(def.replacement()) << newl;
@@ -111,7 +128,7 @@ namespace
             output << keyword("extern") << whitespace << string_literal(linkage.name());
             if (linkage.is_block())
             {
-                output << punctuation("{");
+                output << opening_brace;
                 output.indent();
 
                 write_container(output, linkage, newl);
@@ -136,7 +153,7 @@ namespace
             if (ns.is_inline())
                 output << keyword("inline") << whitespace;
             output << keyword("namespace") << whitespace << identifier(ns.name());
-            output << punctuation("{");
+            output << opening_brace;
             output.indent();
 
             write_container(output, ns, newl);
@@ -152,8 +169,8 @@ namespace
         code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
         if (output)
         {
-            output << keyword("namespace") << whitespace << identifier(alias.name())
-                   << punctuation("=");
+            output << keyword("namespace") << whitespace << identifier(alias.name()) << operator_ws
+                   << punctuation("=") << operator_ws;
             if (output.options() & code_generator::exclude_target)
                 output.excluded(alias);
             else
@@ -188,8 +205,8 @@ namespace
         code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
         if (output)
         {
-            output << keyword("using") << whitespace << identifier(alias.name())
-                   << punctuation("=");
+            output << keyword("using") << whitespace << identifier(alias.name()) << operator_ws
+                   << punctuation("=") << operator_ws;
             if (output.options() & code_generator::exclude_target)
                 output.excluded(alias);
             else
@@ -207,7 +224,7 @@ namespace
             output << identifier(value.name());
             if (value.value())
             {
-                output << punctuation("=");
+                output << operator_ws << punctuation("=") << operator_ws;
                 detail::
                     write_expression(output,
                                      value.value()
@@ -228,16 +245,16 @@ namespace
             output << whitespace << identifier(e.semantic_scope()) << identifier(e.name());
             if (e.has_explicit_type())
             {
-                output << newl << punctuation(":");
+                output << newl << punctuation(":") << operator_ws;
                 detail::write_type(output, e.underlying_type(), "");
             }
 
             if (output.generate_definition() && e.is_definition())
             {
-                output << punctuation("{");
+                output << opening_brace;
                 output.indent();
 
-                auto need_sep = write_container(output, e, [](code_generator::output& out) {
+                auto need_sep = write_container(output, e, [](const code_generator::output& out) {
                     out << punctuation(",") << newl;
                 });
                 if (need_sep)
@@ -298,7 +315,8 @@ namespace
         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(">");
+            output << punctuation("<") << bracket_ws << token_seq(spec.unexposed_arguments())
+                   << bracket_ws << punctuation(">");
     }
 
     void write_bases(code_generator& generator, code_generator::output& output, const cpp_class& c)
@@ -310,10 +328,10 @@ namespace
             if (first && !output.options(base).is_set(code_generator::exclude))
             {
                 first = false;
-                output << newl << punctuation(":");
+                output << newl << punctuation(":") << operator_ws;
             }
             else if (need_sep)
-                output << punctuation(",");
+                output << comma;
             need_sep = generate_base_class(generator, base);
         }
     }
@@ -345,7 +363,7 @@ namespace
             else
             {
                 write_bases(generator, output, c);
-                output << punctuation("{");
+                output << opening_brace;
                 output.indent();
 
                 auto need_sep = false;
@@ -388,7 +406,7 @@ namespace
 
         if (var.default_value())
         {
-            output << punctuation("=");
+            output << operator_ws << punctuation("=") << operator_ws;
             detail::write_expression(output, var.default_value().value());
         }
         return static_cast<bool>(output);
@@ -441,7 +459,8 @@ namespace
             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 << operator_ws << punctuation(":") << operator_ws
+                   << int_literal(std::to_string(var.no_bits()));
             output << punctuation(";") << newl;
         }
         return static_cast<bool>(output);
@@ -457,15 +476,15 @@ namespace
 
     void write_function_parameters(code_generator::output& output, const cpp_function_base& base)
     {
-        output << punctuation("(");
-        auto need_sep = write_container(output, base.parameters(), punctuation(","));
+        output << punctuation("(") << bracket_ws;
+        auto need_sep = write_container(output, base.parameters(), comma);
         if (base.is_variadic())
         {
             if (need_sep)
-                output << punctuation(",");
+                output << comma;
             output << punctuation("...");
         }
-        output << punctuation(")");
+        output << bracket_ws << punctuation(")");
     }
 
     void write_noexcept(code_generator::output& output, const cpp_function_base& base, bool need_ws)
@@ -481,9 +500,9 @@ namespace
             output << keyword("noexcept");
         else
         {
-            output << keyword("noexcept") << punctuation("(");
+            output << keyword("noexcept") << punctuation("(") << bracket_ws;
             detail::write_expression(output, cond);
-            output << punctuation(")");
+            output << bracket_ws << punctuation(")");
         }
     }
 
@@ -495,15 +514,17 @@ namespace
         case cpp_function_declaration:
         case cpp_function_definition:
             if (is_pure_virtual)
-                output << punctuation("=") << int_literal("0");
+                output << operator_ws << punctuation("=") << operator_ws << int_literal("0");
             output << punctuation(";") << newl;
             break;
 
         case cpp_function_defaulted:
-            output << punctuation("=") << keyword("default") << punctuation(";") << newl;
+            output << operator_ws << punctuation("=") << operator_ws << keyword("default")
+                   << punctuation(";") << newl;
             break;
         case cpp_function_deleted:
-            output << punctuation("=") << keyword("delete") << punctuation(";") << newl;
+            output << operator_ws << punctuation("=") << operator_ws << keyword("delete")
+                   << punctuation(";") << newl;
             break;
         }
     }
@@ -543,7 +564,7 @@ namespace
             if (!(output.options() & code_generator::exclude_return)
                 && detail::is_complex_type(func.return_type()))
             {
-                output << punctuation("->");
+                output << operator_ws << punctuation("->") << operator_ws;
                 detail::write_type(output, func.return_type(), "");
             }
             write_function_body(output, func, false);
@@ -591,11 +612,11 @@ namespace
         case cpp_ref_none:
             break;
         case cpp_ref_lvalue:
-            output << punctuation("&");
+            output << operator_ws << punctuation("&") << operator_ws;
             need_ws = false;
             break;
         case cpp_ref_rvalue:
-            output << punctuation("&&");
+            output << operator_ws << punctuation("&&") << operator_ws;
             need_ws = false;
             break;
         }
@@ -642,7 +663,7 @@ namespace
             if (!(output.options() & code_generator::exclude_return)
                 && detail::is_complex_type(func.return_type()))
             {
-                output << punctuation("->");
+                output << operator_ws << punctuation("->") << operator_ws;
                 detail::write_type(output, func.return_type(), "");
             }
 
@@ -775,12 +796,12 @@ namespace
         {
             output << keyword(to_string(param.keyword()));
             if (param.is_variadic())
-                output << punctuation("...");
+                output << operator_ws << punctuation("...");
             if (!param.name().empty())
                 output << whitespace << identifier(param.name());
             if (param.default_type())
             {
-                output << punctuation("=");
+                output << operator_ws << punctuation("=") << operator_ws;
                 detail::write_type(output, param.default_type().value(), "");
             }
         }
@@ -796,7 +817,7 @@ namespace
             detail::write_type(output, param.type(), param.name(), param.is_variadic());
             if (param.default_value())
             {
-                output << punctuation("=");
+                output << operator_ws << punctuation("=") << operator_ws;
                 detail::write_expression(output, param.default_value().value());
             }
         }
@@ -809,14 +830,16 @@ namespace
         code_generator::output output(type_safe::ref(generator), type_safe::ref(param), true);
         if (output)
         {
-            output << keyword("template") << punctuation("<");
+            output << keyword("template") << operator_ws << punctuation("<") << bracket_ws;
             write_container(output, param.parameters(), punctuation(","));
-            output << punctuation(">") << keyword(to_string(param.keyword())) << whitespace;
+            output << bracket_ws << punctuation(">") << operator_ws
+                   << keyword(to_string(param.keyword()));
             if (param.is_variadic())
-                output << punctuation("...");
-            output << identifier(param.name());
+                output << operator_ws << punctuation("...");
+            output << whitespace << identifier(param.name());
             if (param.default_template())
-                output << punctuation("=") << param.default_template().value();
+                output << operator_ws << punctuation("=") << operator_ws
+                       << param.default_template().value();
         }
         return static_cast<bool>(output);
     }
@@ -825,7 +848,7 @@ namespace
                                    bool hide_if_empty)
     {
         if (!hide_if_empty)
-            output << keyword("template") << punctuation("<");
+            output << keyword("template") << operator_ws << punctuation("<") << bracket_ws;
 
         auto need_sep = false;
         auto first    = hide_if_empty;
@@ -835,15 +858,15 @@ namespace
                 && !output.options(*templ.parameters().begin()).is_set(code_generator::exclude))
             {
                 first = false;
-                output << keyword("template") << punctuation("<");
+                output << keyword("template") << operator_ws << punctuation("<") << bracket_ws;
             }
             else if (need_sep)
-                output << punctuation(",");
+                output << comma;
             need_sep = generate_code(*output.generator(), param);
         }
 
         if (!hide_if_empty || need_sep)
-            output << punctuation(">") << newl;
+            output << bracket_ws << punctuation(">") << newl;
     }
 
     bool generate_alias_template(code_generator& generator, const cpp_alias_template& alias)
@@ -922,10 +945,10 @@ namespace
         code_generator::output output(type_safe::ref(generator), type_safe::ref(assert), false);
         if (output)
         {
-            output << keyword("static_assert") << punctuation("(");
+            output << keyword("static_assert") << punctuation("(") << bracket_ws;
             detail::write_expression(output, assert.expression());
-            output << punctuation(",") << string_literal('"' + assert.message() + '"');
-            output << punctuation(");") << newl;
+            output << comma << string_literal('"' + assert.message() + '"');
+            output << bracket_ws << punctuation(");") << newl;
         }
         return static_cast<bool>(output);
     }
@@ -1012,12 +1035,12 @@ void detail::write_template_arguments(code_generator::output&
     if (arguments.size() == 0u)
         return;
 
-    output << punctuation("<");
+    output << punctuation("<") << bracket_ws;
     auto need_sep = false;
     for (auto& arg : arguments)
     {
         if (need_sep)
-            output << punctuation(",");
+            output << comma;
         else
             need_sep = true;
 
@@ -1030,5 +1053,5 @@ void detail::write_template_arguments(code_generator::output&
         else
             DEBUG_UNREACHABLE(detail::assert_handler{});
     }
-    output << punctuation(">");
+    output << bracket_ws << punctuation(">");
 }
diff --git a/src/cpp_type.cpp b/src/cpp_type.cpp
index f675ac9..efd8d7a 100644
--- a/src/cpp_type.cpp
+++ b/src/cpp_type.cpp
@@ -190,6 +190,25 @@ bool detail::is_complex_type(const cpp_type& type) noexcept
 
 namespace
 {
+    void comma(const code_generator::output& output)
+    {
+        output << punctuation(",");
+        if (output.formatting().is_set(formatting_flags::comma_ws))
+            output << whitespace;
+    }
+
+    void bracket_ws(const code_generator::output& output)
+    {
+        if (output.formatting().is_set(formatting_flags::bracket_ws))
+            output << whitespace;
+    }
+
+    void operator_ws(const code_generator::output& output)
+    {
+        if (output.formatting().is_set(formatting_flags::operator_ws))
+            output << whitespace;
+    }
+
     void write_builtin(code_generator::output& output, const cpp_builtin_type& type)
     {
         output << keyword(to_string(type.builtin_type_kind()));
@@ -207,14 +226,15 @@ namespace
 
     void write_decltype(code_generator::output& output, const cpp_decltype_type& type)
     {
-        output << keyword("decltype") << punctuation("(");
+        output << keyword("decltype") << punctuation("(") << bracket_ws;
         detail::write_expression(output, type.expression());
-        output << punctuation(")");
+        output << bracket_ws << punctuation(")");
     }
 
     void write_decltype_auto(code_generator::output& output, const cpp_decltype_auto_type&)
     {
-        output << keyword("decltype") << punctuation("(") << keyword("auto") << punctuation(")");
+        output << keyword("decltype") << punctuation("(") << bracket_ws << keyword("auto")
+               << bracket_ws << punctuation(")");
     }
 
     void write_cv_qualified_prefix(code_generator::output&      output,
@@ -223,7 +243,7 @@ namespace
         detail::write_type_prefix(output, type.type());
 
         if (is_direct_complex(type.type()))
-            output << punctuation("(");
+            output << punctuation("(") << bracket_ws;
 
         if (is_const(type.cv_qualifier()))
             output << whitespace << keyword("const");
@@ -235,7 +255,7 @@ namespace
                                    const cpp_cv_qualified_type& type)
     {
         if (is_direct_complex(type.type()))
-            output << punctuation(")");
+            output << bracket_ws << punctuation(")");
         detail::write_type_suffix(output, type.type());
     }
 
@@ -248,8 +268,11 @@ namespace
     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("(") << bracket_ws;
+        else if (output.formatting().is_set(formatting_flags::ptr_ref_var))
+            output << whitespace;
 
         output << punctuation("*");
     }
@@ -257,15 +280,18 @@ namespace
     void write_pointer_suffix(code_generator::output& output, const cpp_pointer_type& type)
     {
         if (pointer_requires_paren(type))
-            output << punctuation(")");
+            output << bracket_ws << 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("(");
+            output << punctuation("(") << bracket_ws;
+        else if (output.formatting().is_set(formatting_flags::ptr_ref_var))
+            output << whitespace;
 
         if (type.reference_kind() == cpp_ref_lvalue)
             output << punctuation("&");
@@ -278,7 +304,7 @@ namespace
     void write_reference_suffix(code_generator::output& output, const cpp_reference_type& type)
     {
         if (is_direct_complex(type.referee()))
-            output << punctuation(")");
+            output << bracket_ws << punctuation(")");
         detail::write_type_suffix(output, type.referee());
     }
 
@@ -291,7 +317,11 @@ namespace
     {
         output << punctuation("[");
         if (type.size())
+        {
+            output << bracket_ws;
             detail::write_expression(output, type.size().value());
+            output << bracket_ws;
+        }
         output << punctuation("]");
         detail::write_type_suffix(output, type.value_type());
     }
@@ -304,13 +334,13 @@ namespace
     template <typename T>
     void write_parameters(code_generator::output& output, const T& type)
     {
-        output << punctuation("(");
+        output << punctuation("(") << bracket_ws;
 
         auto need_sep = false;
         for (auto& param : type.parameter_types())
         {
             if (need_sep)
-                output << punctuation(",");
+                output << comma;
             else
                 need_sep = true;
             detail::write_type_prefix(output, param);
@@ -319,11 +349,11 @@ namespace
         if (type.is_variadic())
         {
             if (need_sep)
-                output << punctuation(",");
+                output << comma;
             output << punctuation("...");
         }
 
-        output << punctuation(")");
+        output << bracket_ws << punctuation(")");
     }
 
     void write_function_suffix(code_generator::output& output, const cpp_function_type& type)
@@ -361,7 +391,7 @@ namespace
     {
         detail::write_type_prefix(output, type.return_type());
 
-        output << punctuation("(");
+        output << punctuation("(") << bracket_ws;
         detail::write_type_prefix(output, strip_class_type(type.class_type(), nullptr, nullptr));
         output << punctuation("::");
     }
@@ -369,7 +399,7 @@ namespace
     void write_member_function_suffix(code_generator::output&         output,
                                       const cpp_member_function_type& type)
     {
-        output << punctuation(")");
+        output << bracket_ws << punctuation(")");
         write_parameters(output, type);
 
         auto cv  = cpp_cv_none;
@@ -384,9 +414,9 @@ namespace
             output << keyword("volatile");
 
         if (ref == cpp_ref_lvalue)
-            output << punctuation("&");
+            output << operator_ws << punctuation("&") << operator_ws;
         else if (ref == cpp_ref_rvalue)
-            output << punctuation("&&");
+            output << operator_ws << punctuation("&&") << operator_ws;
 
         detail::write_type_suffix(output, type.return_type());
     }
@@ -395,7 +425,7 @@ namespace
                                     const cpp_member_object_type& type)
     {
         detail::write_type_prefix(output, type.object_type());
-        output << punctuation("(");
+        output << punctuation("(") << bracket_ws;
         DEBUG_ASSERT(!detail::is_complex_type(type.class_type()), detail::assert_handler{});
         detail::write_type_prefix(output, type.class_type());
         output << punctuation("::");
@@ -403,7 +433,7 @@ namespace
 
     void write_member_object_suffix(code_generator::output& output, const cpp_member_object_type&)
     {
-        output << punctuation(")");
+        output << bracket_ws << punctuation(")");
     }
 
     void write_template_parameter(code_generator::output&            output,
@@ -419,7 +449,8 @@ namespace
         if (type.arguments_exposed())
             detail::write_template_arguments(output, type.arguments());
         else
-            output << punctuation("<") << token_seq(type.unexposed_arguments()) << punctuation(">");
+            output << punctuation("<") << bracket_ws << token_seq(type.unexposed_arguments())
+                   << bracket_ws << punctuation(">");
     }
 
     void write_dependent(code_generator::output& output, const cpp_dependent_type& type)
@@ -511,6 +542,6 @@ void detail::write_type(code_generator::output& output, const cpp_type& type, st
     if (!name.empty())
         output << whitespace << identifier(name);
     if (is_variadic)
-        output << punctuation("...");
+        output << operator_ws << punctuation("...") << operator_ws;
     write_type_suffix(output, type);
 }
diff --git a/test/code_generator.cpp b/test/code_generator.cpp
index 8a63411..35513d9 100644
--- a/test/code_generator.cpp
+++ b/test/code_generator.cpp
@@ -10,11 +10,14 @@ using namespace cppast;
 
 TEST_CASE("code_generator")
 {
-    SECTION("basic")
-    {
-        // 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;
+    // no need to check much here, as each entity check separately
+    auto code = R"(using type=int;
+
+type* var;
+
+template<template<typename>class... T>
+struct templated{
+};
 
 struct foo{
   int a;
@@ -36,10 +39,62 @@ enum class bar
 void func(int(*)(int));
 
 extern void(* ptr)(int(*)(int))=&func;)";
+    auto file = parse({}, "code_generator.cpp", code);
 
-        auto file = parse({}, "code_generator.cpp", code);
+    SECTION("basic")
+    {
         REQUIRE(get_code(*file) == code);
     }
+    SECTION("formatting")
+    {
+        auto synopsis = R"(using type = int;
+
+type* var;
+
+template <template <typename> class ... T>
+struct templated
+{
+};
+
+struct foo
+{
+  int a;
+
+  auto func(int) -> int(*(*)(int))[42];
+
+private:
+  int const b = 42;
+};
+
+int(*(*(foo::* mptr)(int))(int))[42];
+
+enum class bar
+: int
+{
+  a,
+  b = 42
+};
+
+void func(int(*)(int));
+
+extern void(* ptr)(int(*)(int)) = &func;
+)";
+
+        class formatted_generator : public test_generator
+        {
+        public:
+            using test_generator::test_generator;
+
+        private:
+            formatting do_get_formatting() const override
+            {
+                return formatting_flags::brace_nl | formatting_flags::operator_ws
+                       | formatting_flags::comma_ws;
+            }
+        } generator(code_generator::generation_options{});
+        generate_code(generator, *file);
+        REQUIRE(generator.str() == synopsis);
+    }
     SECTION("exclude target")
     {
         auto code = R"(

From ff2fd014cd3893f29e1ea91505523a84609cda87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonathan=20M=C3=BCller?= <git@foonathan.net>
Date: Sat, 27 May 2017 11:23:29 +0200
Subject: [PATCH 2/2] [breaking] Remove on_container_begin()/end()/leaf()

Replaced with general on_begin()/end()
---
 include/cppast/code_generator.hpp | 49 +++++-------------
 src/code_generator.cpp            | 83 ++++++++++++++++---------------
 2 files changed, 55 insertions(+), 77 deletions(-)

diff --git a/include/cppast/code_generator.hpp b/include/cppast/code_generator.hpp
index a224119..ccf29d4 100644
--- a/include/cppast/code_generator.hpp
+++ b/include/cppast/code_generator.hpp
@@ -170,34 +170,18 @@ namespace cppast
         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.
+            /// \effects Creates it giving the generator and the entity.
             explicit output(type_safe::object_ref<code_generator>   gen,
-                            type_safe::object_ref<const cpp_entity> e, bool is_container)
-            : gen_(gen), options_(gen->do_get_options(*e))
+                            type_safe::object_ref<const cpp_entity> e)
+            : gen_(gen), e_(e), options_(gen->do_get_options(*e))
             {
-                if (is_container)
-                {
-                    gen_->on_container_begin(*e);
-                    e_ = e;
-                }
-                else
-                    gen_->on_leaf(*e);
+                gen_->on_begin(*e_);
             }
 
-            /// \effects If the entity is a container
-            /// and `on_container_begin()` returned `true`,
-            /// calls `on_container_end()`,
-            /// else does nothing.
             ~output() noexcept
             {
-                if (*this && e_)
-                    gen_->on_container_end(e_.value());
+                if (*this)
+                    gen_->on_end(*e_);
             }
 
             output(const output&) = delete;
@@ -365,9 +349,9 @@ namespace cppast
             }
 
         private:
-            type_safe::object_ref<code_generator>     gen_;
-            type_safe::optional_ref<const cpp_entity> e_;
-            generation_options                        options_;
+            type_safe::object_ref<code_generator>   gen_;
+            type_safe::object_ref<const cpp_entity> e_;
+            generation_options                      options_;
         };
 
     protected:
@@ -389,23 +373,16 @@ namespace cppast
             return {};
         }
 
-        /// \effects Will be invoked before code of a container entity is generated.
+        /// \effects Will be invoked before code of an entity is generated.
         /// The base class version has no effect.
-        virtual void on_container_begin(const cpp_entity& e)
+        virtual void on_begin(const cpp_entity& e)
         {
             (void)e;
         }
 
-        /// \effects Will be invoked after all code of a container entity has been generated.
+        /// \effects Will be invoked after all code of an 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.
-        virtual void on_leaf(const cpp_entity& e)
+        virtual void on_end(const cpp_entity& e)
         {
             (void)e;
         }
diff --git a/src/code_generator.cpp b/src/code_generator.cpp
index 8945cb5..eb50362 100644
--- a/src/code_generator.cpp
+++ b/src/code_generator.cpp
@@ -71,7 +71,7 @@ namespace
 
     bool generate_file(code_generator& generator, const cpp_file& f)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(f), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(f));
         if (output)
         {
             auto need_sep = write_container(output, f, newl);
@@ -84,7 +84,7 @@ namespace
 
     bool generate_macro_definition(code_generator& generator, const cpp_macro_definition& def)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(def), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(def));
         if (output)
         {
             output << preprocessor_token("#define") << whitespace << identifier(def.name());
@@ -102,7 +102,7 @@ namespace
 
     bool generate_include_directive(code_generator& generator, const cpp_include_directive& include)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(include), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(include));
         if (output)
         {
             output << preprocessor_token("#include") << whitespace;
@@ -122,7 +122,7 @@ namespace
 
     bool generate_language_linkage(code_generator& generator, const cpp_language_linkage& linkage)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(linkage), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(linkage));
         if (output)
         {
             output << keyword("extern") << whitespace << string_literal(linkage.name());
@@ -147,7 +147,7 @@ namespace
 
     bool generate_namespace(code_generator& generator, const cpp_namespace& ns)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(ns), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(ns));
         if (output)
         {
             if (ns.is_inline())
@@ -166,7 +166,7 @@ namespace
 
     bool generate_namespace_alias(code_generator& generator, const cpp_namespace_alias& alias)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias));
         if (output)
         {
             output << keyword("namespace") << whitespace << identifier(alias.name()) << operator_ws
@@ -182,7 +182,7 @@ namespace
 
     bool generate_using_directive(code_generator& generator, const cpp_using_directive& directive)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(directive), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(directive));
         if (output)
             output << keyword("using") << whitespace << keyword("namespace") << whitespace
                    << directive.target() << punctuation(";") << newl;
@@ -192,8 +192,7 @@ namespace
     bool generate_using_declaration(code_generator&              generator,
                                     const cpp_using_declaration& declaration)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(declaration),
-                                      false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(declaration));
         if (output)
             output << keyword("using") << whitespace << declaration.target() << punctuation(";")
                    << newl;
@@ -202,7 +201,7 @@ namespace
 
     bool generate_type_alias(code_generator& generator, const cpp_type_alias& alias)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias));
         if (output)
         {
             output << keyword("using") << whitespace << identifier(alias.name()) << operator_ws
@@ -218,7 +217,7 @@ namespace
 
     bool generate_enum_value(code_generator& generator, const cpp_enum_value& value)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(value), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(value));
         if (output)
         {
             output << identifier(value.name());
@@ -236,7 +235,7 @@ namespace
 
     bool generate_enum(code_generator& generator, const cpp_enum& e)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(e), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(e));
         if (output)
         {
             output << keyword("enum");
@@ -278,7 +277,7 @@ namespace
 
     bool generate_access_specifier(code_generator& generator, const cpp_access_specifier& access)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(access), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(access));
         if (output)
             write_access_specifier(output, access.access_specifier());
         return static_cast<bool>(output);
@@ -290,7 +289,7 @@ namespace
                      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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(base));
         if (output)
         {
             if (base.is_virtual())
@@ -339,7 +338,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(c));
         if (output)
         {
             if (is_friended(c))
@@ -427,7 +426,7 @@ namespace
 
     bool generate_variable(code_generator& generator, const cpp_variable& var)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var));
         if (output)
         {
             write_storage_class(output, var.storage_class(), var.is_constexpr());
@@ -440,7 +439,7 @@ namespace
 
     bool generate_member_variable(code_generator& generator, const cpp_member_variable& var)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var));
         if (output)
         {
             if (var.is_mutable())
@@ -453,7 +452,7 @@ namespace
 
     bool generate_bitfield(code_generator& generator, const cpp_bitfield& var)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var));
         if (output)
         {
             if (var.is_mutable())
@@ -468,7 +467,7 @@ namespace
 
     bool generate_function_parameter(code_generator& generator, const cpp_function_parameter& param)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(param), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param));
         if (output)
             write_variable_base(output, param, param.name());
         return static_cast<bool>(output);
@@ -533,7 +532,7 @@ namespace
         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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func));
         if (output)
         {
             if (is_friended(func))
@@ -559,7 +558,7 @@ namespace
             else
                 output << identifier(func.name());
             write_function_parameters(output, func);
-            write_noexcept(output, func, false);
+            write_noexcept(output, func, output.formatting().is_set(formatting_flags::operator_ws));
 
             if (!(output.options() & code_generator::exclude_return)
                 && detail::is_complex_type(func.return_type()))
@@ -628,7 +627,7 @@ namespace
         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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func));
         if (output)
         {
             if (is_friended(func))
@@ -658,7 +657,8 @@ namespace
                 output << identifier(func.name());
             write_function_parameters(output, func);
             auto need_ws = write_cv_ref(output, func);
-            write_noexcept(output, func, need_ws);
+            write_noexcept(output, func,
+                           need_ws || output.formatting().is_set(formatting_flags::operator_ws));
 
             if (!(output.options() & code_generator::exclude_return)
                 && detail::is_complex_type(func.return_type()))
@@ -675,7 +675,7 @@ namespace
 
     bool generate_conversion_op(code_generator& generator, const cpp_conversion_op& op)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(op), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(op));
         if (output)
         {
             if (is_friended(op))
@@ -698,7 +698,8 @@ namespace
 
             output << punctuation("(") << punctuation(")");
             auto need_ws = write_cv_ref(output, op);
-            write_noexcept(output, op, need_ws);
+            write_noexcept(output, op,
+                           need_ws || output.formatting().is_set(formatting_flags::operator_ws));
 
             write_suffix_virtual(output, op.virtual_info());
             write_function_body(output, op, is_pure(op.virtual_info()));
@@ -708,7 +709,7 @@ namespace
 
     bool generate_constructor(code_generator& generator, const cpp_constructor& ctor)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(ctor), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(ctor));
         if (output)
         {
             if (is_friended(ctor))
@@ -720,7 +721,7 @@ namespace
 
             output << identifier(ctor.semantic_scope()) << identifier(ctor.name());
             write_function_parameters(output, ctor);
-            write_noexcept(output, ctor, false);
+            write_noexcept(output, ctor, output.formatting().is_set(formatting_flags::operator_ws));
 
             write_function_body(output, ctor, false);
         }
@@ -729,7 +730,7 @@ namespace
 
     bool generate_destructor(code_generator& generator, const cpp_destructor& dtor)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(dtor), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(dtor));
         if (output)
         {
             if (is_friended(dtor))
@@ -737,7 +738,7 @@ namespace
             write_prefix_virtual(output, dtor.virtual_info());
             output << identifier(dtor.semantic_scope()) << identifier(dtor.name())
                    << punctuation("(") << punctuation(")");
-            write_noexcept(output, dtor, false);
+            write_noexcept(output, dtor, output.formatting().is_set(formatting_flags::operator_ws));
 
             write_suffix_virtual(output, dtor.virtual_info());
             write_function_body(output, dtor, is_pure(dtor.virtual_info()));
@@ -771,7 +772,7 @@ namespace
 
     bool generate_friend(code_generator& generator, const cpp_friend& f)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(f), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(f));
         if (output)
         {
             if (auto e = f.entity())
@@ -791,7 +792,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param));
         if (output)
         {
             output << keyword(to_string(param.keyword()));
@@ -811,7 +812,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param));
         if (output)
         {
             detail::write_type(output, param.type(), param.name(), param.is_variadic());
@@ -827,7 +828,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(param));
         if (output)
         {
             output << keyword("template") << operator_ws << punctuation("<") << bracket_ws;
@@ -871,7 +872,7 @@ namespace
 
     bool generate_alias_template(code_generator& generator, const cpp_alias_template& alias)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(alias));
         if (output)
         {
             write_template_parameters(output, alias, true);
@@ -882,7 +883,7 @@ namespace
 
     bool generate_variable_template(code_generator& generator, const cpp_variable_template& var)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(var), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(var));
         if (output)
         {
             write_template_parameters(output, var, true);
@@ -893,7 +894,7 @@ namespace
 
     bool generate_function_template(code_generator& generator, const cpp_function_template& func)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(func), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func));
         if (output)
         {
             write_template_parameters(output, func, true);
@@ -905,7 +906,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(func));
         if (output)
         {
             DEBUG_ASSERT(func.is_full_specialization(), detail::assert_handler{});
@@ -919,7 +920,7 @@ namespace
 
     bool generate_class_template(code_generator& generator, const cpp_class_template& templ)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(templ), true);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(templ));
         if (output)
         {
             write_template_parameters(output, templ, true);
@@ -931,7 +932,7 @@ namespace
     bool 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);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(templ));
         if (output)
         {
             write_template_parameters(output, templ, false);
@@ -942,7 +943,7 @@ namespace
 
     bool generate_static_assert(code_generator& generator, const cpp_static_assert& assert)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(assert), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(assert));
         if (output)
         {
             output << keyword("static_assert") << punctuation("(") << bracket_ws;
@@ -955,7 +956,7 @@ namespace
 
     bool generate_unexposed(code_generator& generator, const cpp_unexposed_entity& entity)
     {
-        code_generator::output output(type_safe::ref(generator), type_safe::ref(entity), false);
+        code_generator::output output(type_safe::ref(generator), type_safe::ref(entity));
         if (output)
             output << token_seq(entity.spelling());
         return static_cast<bool>(output);