Computable Include

computable_include.h

////////////////////////////////////////////////////////////
// <License>
////////////////////////////////////////////////////////////

#pragma once

////////////////////////////////////////////////////////////
//  Title: Computable Include
////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////
//
//  Macro: computable_platform_include(className)
//  ------------------
//
//  A macro used to compute what .h to include based on the class
//  name passed and to the SYSTEM_PLATFORM.
//
//	(start example)
//
//	#define SYSTEM_PLATFORM Win32
//      #include "computable_include.h"
//  
//	#include computable_platform_include(MyClass)
//
//	(end example)
//
//	Will be translate by the C Preprocessor to
//
//	(start example)
//
//	#include "Win32/MyClassWin32.h"
//
//	(end example)
//
//	This permits to avoid all sorts of 
//
//	(start example)
//
//	#if defined(SYSTEM_PLATFORM_Win32)
//	    #include "Win32/MyClassWin32.h"
//	#elif defined(SYSTEM_PLATFORM_Cocoa)
//	    #include "Cocoa/MyClassCocoa.h"
//	#else
//	    #error Platform not supported
//      #endif
//
//	(end example)
//
//  This could be extended as needed as in computable_system_include, computable_graphic_api_include
//
//	See Also:
//
//	      <SYSTEM_PLATFORM>
//
//////////////////////////////////////////////////////////////

#ifndef SYSTEM_PLATFORM
	#error You must define the symbol SYSTEM_PLATFORM
#else
	#define COMPUTABLE_PLATFORM_INCLUDE_QMAKESTR(x) #x
	#define COMPUTABLE_PLATFORM_INCLUDE_MAKESTR(x) COMPUTABLE_PLATFORM_INCLUDE_QMAKESTR(x)
	#define COMPUTABLE_PLATFORM_INCLUDE_MERGE(x, y) ./y/x.h
	#define COMPUTABLE_PLATFORM_INCLUDE_IMP(x) COMPUTABLE_PLATFORM_INCLUDE_MERGE(x, SYSTEM_PLATFORM)
	#define computable_platform_include(x) COMPUTABLE_PLATFORM_INCLUDE_MAKESTR( COMPUTABLE_PLATFORM_INCLUDE_IMP( x ) )
#endif