为什么在C ++中使用（void）1作为无操作？

Question

I'm reviewing a third party codebase and see this definition of an assert macro:

#define assert( x ) \
     if( !( x ) ) { \
        ThrowException( __FILE__, __LINE__ ); \
     } else \
        ((void)1)

What's the point in (void)1 ? How is it better than idiomatic (void)0 ?

Answer 1

(void)1和(void)0之间没有区别。

Answer 2

I think it does not matter that much (and will be optimized away by the compiler). And <cassert> is a standard C++ header (using the standard <assert.h> C header) which defines a standard assert macro, so an application should not re-define it.