示例

//#if MY_MACRO // this directive is commented out
#if MY_OTHER_MACRO || MY_MACRO // this directive is active, single line comments are fine
// your code here
            #endif // doesn't care about white spaces as long the '#' is the frist char in the line

// invalid multiline comments
/*#if MY_MACRO // won't be treated as a directive and won't be able to output the right code
// your code here
#endif*/

// valid multiline comments styles
/*
#if MY_MACRO
// your code here
#endif*/

/*
#if MY_MACRO
// your code here
#endif
*/

使用方法