warning C4003 and errors C2589 and C2059 on: x = std::numeric_limits<int>::max();

This l开发者_Python百科ine works correctly in a small test program, but in the program for which I want it, I get the following compiler complaints:

#include <limits>

x = std::numeric_limits<int>::max();

c:\...\x.cpp(192) : warning C4003: not enough actual parameters for macro 'max'
c:\...\x.cpp(192) : error C2589: '(' : illegal token on right side of '::'
c:\...\x.cpp(192) : error C2059: syntax error : '::'

I get the same results with:

#include <limits>
using namespace std;

x = numeric_limits<int>::max();

Why is it seeing max as the macro max(a,b); ?

This commonly occurs when including a Windows header that defines a min or max macro. If you're using Windows headers, put #define NOMINMAX in your code, or build with the equivalent compiler switch (i.e. use /DNOMINMAX for Visual Studio).

Note that building with NOMINMAX disables use of the macro in your entire program. If you need to use the min or max operations, use std::min() or std::max() from the <algorithm> header.

Other solution would be to wrap function name with parenthesis like this: (std::numeric_limits<int>::max)(). Same applies to std::max.

Not sure it's good solution for this... NOMINMAX is better IMO, but this could be an option in some cases.

Some other header file is polluting the global name space with a max macro. You can fix that by undefining the macro:

#undef max
x = std::numeric_limits<int>::max();

#ifdef max
#pragma push_macro("max")
#undef max
#define _restore_max_
#endif

#include <limits>

//... your stuff that uses limits

#ifdef _restore_max_
#pragma pop_macro("max")
#undef _restore_max_
#endif

(std::numeric_limits::max)()

Easy as pie.

Its definition in for me in Visual Studio 2013 (formatted for better spacing...) is as follows:

static _Ty (max)() _THROW0()
{   // return maximum value
    return (FLT_MAX);
}

So I'm just using FLT_MAX. :) This may not be a universal solution, but it works well in my case, so I thought I would share.