The Visual Studio compiler makes a big deal of int to bool conversions.
For example, if you do:bool bPunct = ispunct(c); // causes warningYou'll get the warning. So how about this attempt at a fix:方法一：bool bPunct = (bool) ispunct(c); // still causes warningNo luck. The help file says its "by design" //for a cast not to hide thewarning. Here are a number of ways to get around //the warning.Use a macro to do the conversion:方法二：#define MKBOOL(_a) ((_a) != 0)bool bPunct = MKBOOL(ispunct(c)); // No warningUse BOOL (which is an int in Windows):方法三： BOOL bPunct = ispunct(c); // No warningDisable the warning (perhaps in your stdafx.h file):
方法四：#pragma warning(disable: 4800) // disables the warning
自我感觉，方法二，比较好
转载自：http://www.davekb.com/browse_programming_tips:warning_C4800_int_forcing_value_to_bool_true_or_false_performance_warning:txt