define文の結合演算子

Tag: C++

Before †

どこかで書き間違ってしまいそうな危ういコード

m_fnSetCommInfo = reinterpret_cast< FnCommSetCommInfo >(
    ::GetProcAddress( m_hLibrary, "SetCommInfo" ) );
m_fnEditEvent = reinterpret_cast< FnCommEditEvent >(
    ::GetProcAddress( m_hLibrary, "EditEvent" ) );
m_fnMoveEvent = reinterpret_cast< FnCommMoveEvent >(
    ::GetProcAddress( m_hLibrary, "MoveEvent" ) );
// ...以降同じようなのが数十行

After †

すっきり！

#define LOAD_FUNCTION(name) \
    m_fn##name = reinterpret_cast< FnComm##name >( \
        ::GetProcAddress( m_hLibrary, #name ) );

    LOAD_FUNCTION( SetCommInfo );
    LOAD_FUNCTION( EditEvent );
    LOAD_FUNCTION( MoveEvent );
    // ... 以下略