Q143208: PRB: Using STL in Windows Program Can Cause Min/Max Conflicts

Article: Q143208
Product(s): Microsoft C Compiler
Version(s): 4.0
Operating System(s): 
Keyword(s): kb3rdparty
Last Modified: 03-AUG-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual C++, version 4.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

A windows-based program that uses the Standard Template Library (STL) will not
compile, and it generates several invalid parameter and syntax errors.

CAUSE
=====

The problem is caused by conflicting definitions of min and max. Min and max are
defined as macros in Windef.h as follows:

     #ifndef NOMINMAX
     #ifndef max
     #define max(a,b)  (((a) > (b)) ? (a) : (b))
     #endif

     #ifndef min
     #define min(a,b)  (((a) < (b)) ? (a) : (b))
     #endif
     #endif  /* NOMINMAX */ 

NOTE: Windef.h is included by Windows.h, which is included in nearly every
Windows-based program.

Min and max are defined as templated functions in the Standard Template Library
(STL). The following definitions of min and max can be found in the file
Algobase.h:

     template <class T>
     inline const T& min(const T& a, const T& b) {
         return b < a ? b : a;
     }
     template <class T, class Compare>
     inline const T& min(const T& a, const T& b, Compare comp) {
         return comp(b, a) ? b : a;
     }
     template <class T>
     inline const T& max(const T& a, const T& b) {
         return  a < b ? b : a;
     }
     template <class T, class Compare>
     inline const T& max(const T& a, const T& b, Compare comp) {
         return comp(a, b) ? b : a;
     }

Because the Windef.h definition is a macro, the function definitions cause syntax
errors when both Windef.h (or Windows.h) and Algobase.h (from the STL) are
included. The precise errors will depend on the order in which the two are
compiled.

RESOLUTION
==========

Simply define the NOMINMAX preprocessor symbol. This can be done in the
Developer Studio project under Build, Settings, on the C/C++ tab, in the
Preprocessor category. This will suppress the min and max definitions in
Windef.h.

STATUS
======

This behavior is by design.

Additional query words:

======================================================================
Keywords          : kb3rdparty 
Technology        : kbVCsearch kbVC400 kbAudDeveloper
Version           : 4.0
Issue type        : kbprb

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.