타입캐스팅 만들기( 변환 함수 )

※ 자신이 만든 클래스에서 다른 자료형과 호환되게 하기에 유용!

operator 변환타입()

{

          /* code */ 

          return 변환타입;

}

예시) 

D3DXCOLOR -> DWORD 변환
 

D3DXCOLOR foo( 255.f, 123.f, 456.f, 255.f );

DWORD color = foo;

 
<d3dx9math.h>

typedef struct D3DXCOLOR

{ 
     ...
     // casting
    

operator DWORD () const; 
     ... 
}

<dxdx9math.inl>

D3DXINLINE

D3DXCOLOR::operator DWORD () const

{

    DWORD dwR = r >= 1.0f ? 0xff : r <= 0.0f ? 0x00 : (DWORD) (r * 255.0f + 0.5f);

    DWORD dwG = g >= 1.0f ? 0xff : g <= 0.0f ? 0x00 : (DWORD) (g * 255.0f + 0.5f);

    DWORD dwB = b >= 1.0f ? 0xff : b <= 0.0f ? 0x00 : (DWORD) (b * 255.0f + 0.5f);

    DWORD dwA = a >= 1.0f ? 0xff : a <= 0.0f ? 0x00 : (DWORD) (a * 255.0f + 0.5f);

    return (dwA << 24) | (dwR << 16) | (dwG << 8) | dwB;

}