cnicholson.net » Stupid C++ Tricks: do/while(0) and C4127A nice little quickie: I briefly discuss in my assert ramblings why it’s important to wrap all of your multi-line macros in do/while(0) blocks. An unfortunate side-effect of this is that the construction // NOISY CODE #define MULTI_LINE_MACRO \ do { \ std::printf("Hello "); \ std::printf("world!\n"); \ } while (0) will trigger C4127: “Conditional expression is constant” in Visual Studio 2003/200
