include/wx/cpp.h

   1 /*
   2  *  Name:        wx/cpp.h
   3  *  Purpose:     Various preprocessor helpers
   4  *  Author:      Vadim Zeitlin
   5  *  Created:     2006-09-30
   6  *  RCS-ID:      $Id$
   7  *  Copyright:   (c) 2006 Vadim Zeitlin <vadim@wxwindows.org>
   8  *  Licence:     wxWindows licence
   9  */
  10
  11 /* THIS IS A C FILE, DON'T USE C++ FEATURES (IN PARTICULAR COMMENTS) IN IT */
  12
  13 #ifndef _WX_CPP_H_
  14 #define _WX_CPP_H_
  15
  16 /* wxCONCAT works like preprocessor ## operator but also works with macros */
  17 #define wxCONCAT_HELPER(text, line) text ## line
  18 #define wxCONCAT(text, line)        wxCONCAT_HELPER(text, line)
  19
  20 /* wxSTRINGIZE works as the preprocessor # operator but also works with macros */
  21 #define wxSTRINGIZE_HELPER(x)       #x
  22 #define wxSTRINGIZE(x)              wxSTRINGIZE_HELPER(x)
  23
  24 /* a Unicode-friendly version of wxSTRINGIZE_T */
  25 #define wxSTRINGIZE_T(x)            wxAPPLY_T(wxSTRINGIZE(x))
  26
  27 /*
  28    Helper macros for wxMAKE_UNIQUE_NAME: normally this works by appending the
  29    current line number to the given identifier to reduce the probability of the
  30    conflict (it may still happen if this is used in the headers, hence you
  31    should avoid doing it or provide unique prefixes then) but we have to do it
  32    differently for VC++
  33   */
  34 #if defined(__VISUALC__) && (__VISUALC__ >= 1300)
  35     /*
  36        __LINE__ handling is completely broken in VC++ when using "Edit and
  37        Continue" (/ZI option) and results in preprocessor errors if we use it
  38        inside the macros. Luckily VC7 has another standard macro which can be
  39        used like this and is even better than __LINE__ because it is globally
  40        unique.
  41      */
  42 #   define wxCONCAT_LINE(text)         wxCONCAT(text, __COUNTER__)
  43 #else /* normal compilers */
  44 #   define wxCONCAT_LINE(text)         wxCONCAT(text, __LINE__)
  45 #endif
  46
  47 /* Create a "unique" name with the given prefix */
  48 #define wxMAKE_UNIQUE_NAME(text)    wxCONCAT_LINE(text)
  49
  50 /*
  51    This macro can be passed as argument to another macro when you don't have
  52    anything to pass in fact.
  53  */
  54 #define wxEMPTY_PARAMETER_VALUE /* Fake macro parameter value */
  55
  56 #endif // _WX_CPP_H_
  57