vc 使用__leave来优化try catch

The __leave keyword

The __leave keyword is valid within a try-finally statement block. The effect of __leave is to jump to the end of the try-finally block. The termination handler is immediately executed. Although a goto statement can be used to accomplish the same result, a goto statement causes stack unwinding. The __leave statement is more efficient because it does not involve stack unwinding.

__try/__finally在使用时，如果在__try块中有goto、return等语句会引起局部展开（local   unwind），影响程序效率，所以在__try快中使用__leave

 

总之：__leave跳出try-finally块，goto会造成栈的释放，而__leave不会造成释放，从而提高效率。