Add basic_cpp_entity_ref generalization

include/cppast/cpp_entity_ref.hpp

@@ -0,0 +1,52 @@
+// 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_CPP_ENTITY_REF_HPP_INCLUDED
+#define CPPAST_CPP_ENTITY_REF_HPP_INCLUDED
+
+#include <cppast/cpp_entity_index.hpp>
+#include <cppast/cpp_entity_type.hpp>
+
+namespace cppast
+{
+    /// A basic reference to some kind of [cppast::cpp_entity]().
+    template <typename T, cpp_entity_type Type>
+    class basic_cpp_entity_ref
+    {
+    public:
+        /// \effects Creates it giving it the target id and name.
+        /// \requires An entity of matching type must eventually register in the [cppast::cpp_entity_index]() using that id.
+        basic_cpp_entity_ref(cpp_entity_id target_id, std::string target_name)
+        : target_(std::move(target_id)), name_(std::move(target_name))
+        {
+        }
+
+        /// \returns The name of the reference, as spelled in the source code.
+        const std::string& name() const noexcept
+        {
+            return name_;
+        }
+
+        /// \returns The [cppast::cpp_entity_id]() of the entity it refers to.
+        const cpp_entity_id& id() const noexcept
+        {
+            return target_;
+        }
+
+        /// \returns The [cppast::cpp_entity]() it refers to.
+        const T& get(const cpp_entity_index& idx) const noexcept
+        {
+            return detail::downcast_entity<const T&>(idx.lookup(target_).value(), Type);
+        }
+
+    private:
+        cpp_entity_id target_;
+        std::string   name_;
+    };
+
+    /// A [cppast::basic_cpp_entity_ref]() to any [cppast::cpp_entity]().
+    using cpp_entity_ref = basic_cpp_entity_ref<cpp_entity, cpp_entity_type::count>;
+} // namespace cppast
+
+#endif // CPPAST_CPP_ENTITY_REF_HPP_INCLUDED

include/cppast/cpp_entity_type.hpp

@@ -17,6 +17,8 @@ namespace cppast
         namespace_t,
         namespace_alias_t,
         using_directive_t,
+
+        count,
     };
 
     /// \returns Whether or not a given entity type is one derived from [cppast::cpp_scope]().
@@ -28,8 +30,8 @@ namespace cppast
         template <typename T, typename Org>
         T downcast_entity(Org& org, cpp_entity_type dest_type) noexcept
         {
-            DEBUG_ASSERT(org.type() == dest_type, detail::precondition_error_handler{},
+            DEBUG_ASSERT(dest_type == cpp_entity_type::count || org.type() == dest_type,
-                         "invalid downcast");
+                         detail::precondition_error_handler{}, "invalid downcast");
             return static_cast<T>(org);
         }
     } // namespace detail

include/cppast/cpp_namespace.hpp

@@ -6,6 +6,7 @@
 #define CPPAST_CPP_NAMESPACE_HPP_INCLUDED
 
 #include <cppast/cpp_entity_index.hpp>
+#include <cppast/cpp_entity_ref.hpp>
 #include <cppast/cpp_scope.hpp>
 
 namespace cppast
@@ -56,41 +57,16 @@ namespace cppast
         {
         }
 
-        cpp_entity_type do_get_entity_type() const noexcept override;
+        cpp_entity_type do_get_entity_type() const noexcept override
+        {
+            return cpp_entity_type::namespace_t;
+        }
 
         bool inline_;
     };
 
     /// A reference to a [cppast::cpp_namespace]().
-    class cpp_namespace_ref
+    using cpp_namespace_ref = basic_cpp_entity_ref<cpp_namespace, cpp_entity_type::namespace_t>;
-    {
-    public:
-        /// \effects Creates it giving it the target id and name.
-        /// \requires A [cppast::cpp_namespace]() must register in the [cppast::cpp_entity_index]() with that id.
-        cpp_namespace_ref(cpp_entity_id target_id, std::string target_name)
-        : target_(std::move(target_id)), name_(std::move(target_name))
-        {
-        }
-
-        /// \returns The name of the reference, as spelled in the source code.
-        const std::string& name() const noexcept
-        {
-            return name_;
-        }
-
-        /// \returns The [cppast::cpp_entity_id]() of the namespace it refers to.
-        const cpp_entity_id& id() const noexcept
-        {
-            return target_;
-        }
-
-        /// \returns The [cppast::cpp_namespace]() it refers to.
-        const cpp_namespace& get(const cpp_entity_index& idx) const noexcept;
-
-    private:
-        cpp_entity_id target_;
-        std::string   name_;
-    };
 
     /// A [cppast::cpp_entity]() modelling a namespace alias.
     class cpp_namespace_alias final : public cpp_entity
@@ -119,7 +95,10 @@ namespace cppast
         {
         }
 
-        cpp_entity_type do_get_entity_type() const noexcept override;
+        cpp_entity_type do_get_entity_type() const noexcept override
+        {
+            return cpp_entity_type::namespace_alias_t;
+        }
 
         cpp_namespace_ref target_;
     };
@@ -151,7 +130,10 @@ namespace cppast
         {
         }
 
-        cpp_entity_type do_get_entity_type() const noexcept override;
+        cpp_entity_type do_get_entity_type() const noexcept override
+        {
+            return cpp_entity_type::using_directive_t;
+        }
 
         cpp_entity_id target_;
     };

src/cpp_entity_type.cpp

@@ -16,6 +16,7 @@ bool cppast::is_scope(cpp_entity_type type) noexcept
     case cpp_entity_type::file_t:
     case cpp_entity_type::namespace_alias_t:
     case cpp_entity_type::using_directive_t:
+    case cpp_entity_type::count:
         break;
     }
 

src/cpp_namespace.cpp

@@ -1,30 +0,0 @@
-// 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_namespace.hpp>
-
-#include <cppast/cpp_entity_type.hpp>
-
-using namespace cppast;
-
-cpp_entity_type cpp_namespace::do_get_entity_type() const noexcept
-{
-    return cpp_entity_type::namespace_t;
-}
-
-const cpp_namespace& cpp_namespace_ref::get(const cpp_entity_index& idx) const noexcept
-{
-    return detail::downcast_entity<const cpp_namespace&>(idx.lookup(target_).value(),
-                                                         cpp_entity_type::namespace_t);
-}
-
-cpp_entity_type cpp_namespace_alias::do_get_entity_type() const noexcept
-{
-    return cpp_entity_type::namespace_alias_t;
-}
-
-cpp_entity_type cpp_using_directive::do_get_entity_type() const noexcept
-{
-    return cpp_entity_type::using_directive_t;
-}