ceph/src/boost/boost/test/tools/detail/print_helper.hpp

   1 //  (C) Copyright Gennadiy Rozental 2001.
   2 //  Distributed under the Boost Software License, Version 1.0.
   3 //  (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //  See http://www.boost.org/libs/test for the library home page.
   7 //
   8 //  File        : $RCSfile$
   9 //
  10 //  Version     : $Revision: 74248 $
  11 //
  12 //  Description : defines level of indiration facilitating workarounds for non printable types
  13 // ***************************************************************************
  14
  15 #ifndef BOOST_TEST_TOOLS_IMPL_COMMON_HPP_012705GER
  16 #define BOOST_TEST_TOOLS_IMPL_COMMON_HPP_012705GER
  17
  18 // Boost.Test
  19 #include <boost/test/detail/config.hpp>
  20 #include <boost/test/detail/global_typedef.hpp>
  21 #include <boost/test/detail/workaround.hpp>
  22
  23 // Boost
  24 #include <boost/mpl/or.hpp>
  25 #include <boost/static_assert.hpp>
  26 #include <boost/type_traits/is_array.hpp>
  27 #include <boost/type_traits/is_function.hpp>
  28 #include <boost/type_traits/is_abstract.hpp>
  29 #include <boost/type_traits/has_left_shift.hpp>
  30
  31 #include <limits>
  32
  33 #if !defined(BOOST_NO_CXX11_NULLPTR)
  34 #include <cstddef>
  35 #endif
  36
  37 #include <boost/test/detail/suppress_warnings.hpp>
  38
  39 //____________________________________________________________________________//
  40
  41 namespace boost {
  42 namespace test_tools {
  43 namespace tt_detail {
  44
  45 // ************************************************************************** //
  46 // **************          boost_test_print_type               ************** //
  47 // ************************************************************************** //
  48
  49     namespace impl {
  50         template <class T>
  51         std::ostream& boost_test_print_type(std::ostream& ostr, T const& t) {
  52             BOOST_STATIC_ASSERT_MSG( (boost::has_left_shift<std::ostream,T>::value),
  53                                     "Type has to implement operator<< to be printable");
  54             ostr << t;
  55             return ostr;
  56         }
  57
  58         struct boost_test_print_type_impl {
  59             template <class R>
  60             std::ostream& operator()(std::ostream& ostr, R const& r) const {
  61                 return boost_test_print_type(ostr, r);
  62             }
  63         };
  64     }
  65
  66     // To avoid ODR violations, see N4381
  67     template <class T> struct static_const { static const T value; };
  68     template <class T> const T static_const<T>::value = T();
  69
  70     namespace {
  71         static const impl::boost_test_print_type_impl& boost_test_print_type =
  72             static_const<impl::boost_test_print_type_impl>::value;
  73     }
  74
  75
  76 // ************************************************************************** //
  77 // **************                print_log_value               ************** //
  78 // ************************************************************************** //
  79
  80 template<typename T>
  81 struct print_log_value {
  82     void    operator()( std::ostream& ostr, T const& t )
  83     {
  84         typedef typename mpl::or_<is_array<T>,is_function<T>,is_abstract<T> >::type cant_use_nl;
  85
  86         std::streamsize old_precision = set_precision( ostr, cant_use_nl() );
  87
  88         //ostr << t;
  89         using boost::test_tools::tt_detail::boost_test_print_type;
  90         boost_test_print_type(ostr, t);
  91
  92         if( old_precision != (std::streamsize)-1 )
  93             ostr.precision( old_precision );
  94     }
  95
  96     std::streamsize set_precision( std::ostream& ostr, mpl::false_ )
  97     {
  98         if( std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::radix == 2 )
  99             return ostr.precision( 2 + std::numeric_limits<T>::digits * 301/1000 );
 100         else if ( std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::radix == 10 ) {
 101 #ifdef BOOST_NO_CXX11_NUMERIC_LIMITS
 102             // (was BOOST_NO_NUMERIC_LIMITS_LOWEST but now deprecated).
 103             // No support for std::numeric_limits<double>::max_digits10,
 104             // so guess that a couple of guard digits more than digits10 will display any difference.
 105             return ostr.precision( 2 + std::numeric_limits<T>::digits10 );
 106 #else
 107             // std::numeric_limits<double>::max_digits10; IS supported.
 108             // Any noisy or guard digits needed to display any difference are included in max_digits10.
 109             return ostr.precision( std::numeric_limits<T>::max_digits10 );
 110 #endif
 111         }
 112         // else if T is not specialized for std::numeric_limits<>,
 113         // then will just get the default precision of 6 digits.
 114         return (std::streamsize)-1;
 115     }
 116
 117     std::streamsize set_precision( std::ostream&, mpl::true_ ) { return (std::streamsize)-1; }
 118 };
 119
 120 //____________________________________________________________________________//
 121
 122 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 123 template<typename T, std::size_t N >
 124 struct print_log_value< T[N] > {
 125     void    operator()( std::ostream& ostr, T const* t )
 126     {
 127         ostr << t;
 128     }
 129 };
 130 #endif
 131
 132 //____________________________________________________________________________//
 133
 134 template<>
 135 struct BOOST_TEST_DECL print_log_value<bool> {
 136     void    operator()( std::ostream& ostr, bool t );
 137 };
 138
 139 //____________________________________________________________________________//
 140
 141 template<>
 142 struct BOOST_TEST_DECL print_log_value<char> {
 143     void    operator()( std::ostream& ostr, char t );
 144 };
 145
 146 //____________________________________________________________________________//
 147
 148 template<>
 149 struct BOOST_TEST_DECL print_log_value<unsigned char> {
 150     void    operator()( std::ostream& ostr, unsigned char t );
 151 };
 152
 153 //____________________________________________________________________________//
 154
 155 template<>
 156 struct BOOST_TEST_DECL print_log_value<char const*> {
 157     void    operator()( std::ostream& ostr, char const* t );
 158 };
 159
 160 //____________________________________________________________________________//
 161
 162 template<>
 163 struct BOOST_TEST_DECL print_log_value<wchar_t const*> {
 164     void    operator()( std::ostream& ostr, wchar_t const* t );
 165 };
 166
 167 #if !defined(BOOST_NO_CXX11_NULLPTR)
 168 template<>
 169 struct print_log_value<std::nullptr_t> {
 170     // declaration and definition is here because of #12969 https://svn.boost.org/trac10/ticket/12969
 171     void    operator()( std::ostream& ostr, std::nullptr_t /*t*/ ) {
 172         ostr << "nullptr";
 173     }
 174 };
 175 #endif
 176
 177 //____________________________________________________________________________//
 178
 179 // ************************************************************************** //
 180 // **************                 print_helper                 ************** //
 181 // ************************************************************************** //
 182 // Adds level of indirection to the output operation, allowing us to customize
 183 // it for types that do not support operator << directly or for any other reason
 184
 185 template<typename T>
 186 struct print_helper_t {
 187     explicit    print_helper_t( T const& t ) : m_t( t ) {}
 188
 189     T const&    m_t;
 190 };
 191
 192 //____________________________________________________________________________//
 193
 194 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 195 // Borland suffers premature pointer decay passing arrays by reference
 196 template<typename T, std::size_t N >
 197 struct print_helper_t< T[N] > {
 198     explicit    print_helper_t( T const * t ) : m_t( t ) {}
 199
 200     T const *   m_t;
 201 };
 202 #endif
 203
 204 //____________________________________________________________________________//
 205
 206 template<typename T>
 207 inline print_helper_t<T>
 208 print_helper( T const& t )
 209 {
 210     return print_helper_t<T>( t );
 211 }
 212
 213 //____________________________________________________________________________//
 214
 215 template<typename T>
 216 inline std::ostream&
 217 operator<<( std::ostream& ostr, print_helper_t<T> const& ph )
 218 {
 219     print_log_value<T>()( ostr, ph.m_t );
 220
 221     return ostr;
 222 }
 223
 224 //____________________________________________________________________________//
 225
 226 } // namespace tt_detail
 227
 228 // ************************************************************************** //
 229 // **************       BOOST_TEST_DONT_PRINT_LOG_VALUE        ************** //
 230 // ************************************************************************** //
 231
 232 #define BOOST_TEST_DONT_PRINT_LOG_VALUE( the_type )         \
 233 namespace boost{ namespace test_tools{ namespace tt_detail{ \
 234 template<>                                                  \
 235 struct print_log_value<the_type > {                         \
 236     void    operator()( std::ostream&, the_type const& ) {} \
 237 };                                                          \
 238 }}}                                                         \
 239 /**/
 240
 241 } // namespace test_tools
 242 } // namespace boost
 243
 244 #include <boost/test/detail/enable_warnings.hpp>
 245
 246 #endif // BOOST_TEST_TOOLS_IMPL_COMMON_HPP_012705GER