D for Win32

Instead of the:

	#include <windows.h>
	

	import std.c.windows.windows;
	

Calling Conventions

	extern (Windows)
	{
		... function declarations ...
	}
	

For functions that in C would be __declspec(dllimport) or __declspec(dllexport), use the export attribute:

	export void func(int foo);
	

Windows Executables

These are required:

1. Instead of a main function serving as the entry point, a WinMain function is needed.
2. WinMain must follow this form:

   import std.c.windows.windows;
   
   extern (C) void gc_init();
   extern (C) void gc_term();
   extern (C) void _minit();
   extern (C) void _moduleCtor();
   extern (C) void _moduleUnitTests();
   
   extern (Windows)
   int WinMain(HINSTANCE hInstance,
   	HINSTANCE hPrevInstance,
   	LPSTR lpCmdLine,
   	int nCmdShow)
   {
       int result;
   
       gc_init();			// initialize garbage collector
       _minit();			// initialize module constructor table
   
       try
       {
   	_moduleCtor();		// call module constructors
   	_moduleUnitTests();	// run unit tests (optional)
   
   	result = myWinMain(hInstance, hPrevInstance, lpCmdLine, nCmdShow);
       }
   
       catch (Object o)		// catch any uncaught exceptions
       {
   	MessageBoxA(null, cast(char *)o.toString(), "Error",
   		    MB_OK | MB_ICONEXCLAMATION);
   	result = 0;		// failed
       }
   
       gc_term();			// run finalizers; terminate garbage collector
       return result;
   }
   
   int myWinMain(HINSTANCE hInstance,
   	HINSTANCE hPrevInstance,
   	LPSTR lpCmdLine,
   	int nCmdShow)
   {
       ... insert user code here ...
   }
   	

   The myWinMain() function is where the user code goes, the rest of WinMain is boilerplate to initialize and shut down the D runtime system.
3. A .def (Module Definition File) with at least the following two lines in it:

   EXETYPE NT
   SUBSYSTEM WINDOWS
   	

   Without those, Win32 will open a text console window whenever the application is run.
4. The presence of WinMain() is recognized by the compiler causing it to emit a reference to __acrtused_dll and the phobos.lib runtime library.

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