int转换为bool

Question

In VS 10 I get a warning: 在VS 10中，我得到警告：

warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)

trying to compile 试图编译

int x ;
static_cast<bool>(x);

How is it possible to write a code which doesn`t cause this warning? 如何编写不会引起此警告的代码？

Answer 1

怎么样呢？

x != 0

Answer 2

int x ;
bool b1 = !!x;  // common idiom; get used to it.  "Newcomers" just need to learn the idiom.
bool b2 = x!=0; // another way, less idiomatic

Answer 3

It is a stupid warning and can be ignored/disabled. 这是一个愚蠢的警告，可以忽略/禁用。 There is no performance issue as far as I know. 据我所知，没有性能问题。