Strange C++ errors with code that has min()/max() calls

Question

I'm seeing strange errors when my C++ code has min() or max() calls. I'm using Visual C++ compilers.

Answer 1

Check if your code is including the windows.h header file and either your code or other third-party headers have their own min()/max() definitions. If yes, then prepend your windows.h inclusion with a definition of NOMINMAX like this:

#define NOMINMAX
#include <windows.h>

Answer 2

Another possibility could be from side effects. Most min/max macros will include the parameters multiple times and may not do what you expect. Errors and warnings could also be generated.

max(a,i++) expands as ((a) > (i++) ? (a) : (i++))

afterwards i is either plus 1 or plus 2

The () in the expansion are to avoid problems if you call it with formulae. Try expanding max(a,b+c)

Answer 3

Since Windows defines this as a function-style macro, the following workaround is available:

int i = std::min<int>(3,5);

This works because the macro min() is expanded only when min is followed by (, and not when it's followed by <.