IDL: Generate union type containers

Source/bindings/templates/union.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file has been auto-generated by {{code_generator}}. DO NOT MODIFY!
 
 #ifndef {{macro_guard}}
 #define {{macro_guard}}
 
+{% for filename in header_includes %}
+#include "{{filename}}"
+{% endfor %}
+
 namespace blink {
 
+{% for decl in header_forward_decls %}
+class {{decl}};
+{% endfor %}
+
 {% for container in containers %}
 class {{container.cpp_class}} final {
-    // FIXME: Implement
+    ALLOW_ONLY_INLINE_ALLOCATION();
+public:
+    {{container.cpp_class}}();
+    bool isNull() const { return m_specificTypeFlag == 0; }
+
+    {% for member in container.members %}
+    bool is{{member.type_name}}() const { return m_specificTypeFlag == {{member.index}}; }
+    {{member.rvalue_cpp_type}} getAs{{member.type_name}}();

[Jens Widell, 2014/10/28 11:31:38]

Might be a good idea to inline these?

[bashi, 2014/10/29 01:34:33]

Unfortunately, forward declarations are used for interface types (e.g. NodeList)
in this header files so we can't inline these. We can add includes, but I
thought it will slow down build speed.

+    void set{{member.type_name}}({{member.rvalue_cpp_type}});
+
+    {% endfor %}
+private:
+    unsigned m_specificTypeFlag;

[Jens Widell, 2014/10/28 11:31:38]

For bonus points (nice when debugging) you could use a generated (private)
enumeration type here, I guess.

[bashi, 2014/10/29 01:34:33]

Done.

+
+    {% for member in container.members %}
+    {{member.cpp_type}} m_{{member.cpp_name}};
+    {% endfor %}
 };
 
+class V8{{container.cpp_class}} {
+public:
+    static void toImpl(v8::Isolate*, v8::Handle<v8::Value>, {{container.cpp_class}}&, ExceptionState&);
+};
+
+v8::Handle<v8::Value> toV8({{container.cpp_class}}&, v8::Handle<v8::Object>, v8::Isolate*);
+
+template <class CallbackInfo>
+inline void v8SetReturnValue(const CallbackInfo& callbackInfo, {{container.cpp_class}}& impl)
+{
+    v8SetReturnValue(callbackInfo, toV8(impl, callbackInfo.Holder(), callbackInfo.GetIsolate()));
+}
+
 {% endfor %}
 } // namespace blink
 
 #endif // {{macro_guard}}