libs/type_traits/test/decay_test.cpp

   1
   2 //  (C) Copyright John Maddock & Thorsten Ottosen 2005.
   3 //  Use, modification and distribution are subject to the
   4 //  Boost Software License, Version 1.0. (See accompanying file
   5 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include "test.hpp"
   8 #include "check_integral_constant.hpp"
   9 #ifdef TEST_STD
  10 #  include <type_traits>
  11 #else
  12 #  include <boost/type_traits/decay.hpp>
  13 #  include <boost/type_traits/is_same.hpp>
  14 #endif
  15 #include <iostream>
  16 #include <string>
  17 #include <utility>
  18
  19 #ifdef BOOST_INTEL
  20 //  remark #383: value copied to temporary, reference to temporary used
  21 //     std::pair<std::string, int>        p2 = boost::make_pair( "foo", 1 );
  22 //                                                                      ^
  23 #pragma warning(disable:383)
  24 #endif
  25
  26 namespace boost
  27 {
  28
  29     int proc1()
  30     {
  31        return 0;
  32     }
  33     int proc2(int c)
  34     {
  35        return c;
  36     }
  37
  38     //
  39     // An almost optimal version of std::make_pair()
  40     //
  41     template< class F, class S >
  42     inline std::pair< BOOST_DEDUCED_TYPENAME tt::decay<const F>::type,
  43                       BOOST_DEDUCED_TYPENAME tt::decay<const S>::type >
  44     make_pair( const F& f, const S& s )
  45     {
  46         return std::pair< BOOST_DEDUCED_TYPENAME tt::decay<const F>::type,
  47                           BOOST_DEDUCED_TYPENAME tt::decay<const S>::type >( f, s );
  48     }
  49
  50     /*
  51     This overload will mess up vc7.1
  52
  53     template< class F, class S >
  54     inline std::pair< BOOST_DEDUCED_TYPENAME ::tt::decay<F>::type,
  55                       BOOST_DEDUCED_TYPENAME ::tt::decay<S>::type >
  56     make_pair( F& f, S& s )
  57     {
  58         return std::pair< BOOST_DEDUCED_TYPENAME ::tt::decay<F>::type,
  59                           BOOST_DEDUCED_TYPENAME ::tt::decay<S>::type >( f, s );
  60     }
  61     */
  62 }
  63
  64 TT_TEST_BEGIN(is_class)
  65
  66    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  67           ::tt::decay<int>::type,int>::value),
  68                                   true );
  69    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  70           ::tt::decay<char[2]>::type,char*>::value),
  71                                  true );
  72    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  73           ::tt::decay<char[2][3]>::type,char(*)[3]>::value),
  74                                  true );
  75    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  76           ::tt::decay<const char[2]>::type,const char*>::value),
  77                                   true );
  78    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  79           ::tt::decay<wchar_t[2]>::type,wchar_t*>::value),
  80                                   true );
  81    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  82           ::tt::decay<const wchar_t[2]>::type,const wchar_t*>::value),
  83                                   true );
  84    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  85           ::tt::decay<const wchar_t[2]>::type,const wchar_t*>::value),
  86                                   true );
  87
  88    typedef int f1_type(void);
  89    typedef int f2_type(int);
  90
  91    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  92           ::tt::decay<f1_type>::type,int (*)(void)>::value),
  93                                   true );
  94    BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_same<
  95           ::tt::decay<f2_type>::type,int (*)(int)>::value),
  96                                   true );
  97
  98    std::pair<std::string,std::string> p  = boost::make_pair( "foo", "bar" );
  99    std::pair<std::string, int>        p2 = boost::make_pair( "foo", 1 );
 100 #ifndef BOOST_NO_STD_WSTRING
 101    std::pair<std::wstring,std::string> p3  = boost::make_pair( L"foo", "bar" );
 102    std::pair<std::wstring, int>        p4  = boost::make_pair( L"foo", 1 );
 103 #endif
 104
 105    //
 106    // Todo: make these work sometime. The test id not directly
 107    //       related to decay<T>::type and can be avoided for now.
 108    //
 109    /*
 110    int array[10];
 111    std::pair<int*,int*> p5 = boost::make_pair( array, array );
 112 #ifndef __BORLANDC__
 113    std::pair<int(*)(void), int(*)(int)> p6 = boost::make_pair(boost::proc1, boost::proc2);
 114    p6.first();
 115    p6.second(1);
 116 #endif
 117    */
 118
 119 TT_TEST_END
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