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
22// Boost
23#include <boost/mpl/or.hpp>
24#include <boost/static_assert.hpp>
25#include <boost/type_traits/is_array.hpp>
26#include <boost/type_traits/is_function.hpp>
27#include <boost/type_traits/is_abstract.hpp>
28#include <boost/type_traits/has_left_shift.hpp>
29
30#include <ios>
31#include <iostream>
32#include <limits>
33
34#if !defined(BOOST_NO_CXX11_NULLPTR)
35#include <cstddef>
36#endif
37
38#include <boost/test/detail/suppress_warnings.hpp>
39
40//____________________________________________________________________________//
41
42namespace boost {
43namespace test_tools {
44namespace tt_detail {
45
46// ************************************************************************** //
47// ************** boost_test_print_type ************** //
48// ************************************************************************** //
49
50 namespace impl {
51 template <class T>
52 std::ostream& boost_test_print_type(std::ostream& ostr, T const& t) {
53 BOOST_STATIC_ASSERT_MSG( (boost::has_left_shift<std::ostream,T>::value),
54 "Type has to implement operator<< to be printable");
55 ostr << t;
56 return ostr;
57 }
58
59 struct boost_test_print_type_impl {
60 template <class R>
61 std::ostream& operator()(std::ostream& ostr, R const& r) const {
62 return boost_test_print_type(ostr, r);
63 }
64 };
65 }
66
67 // To avoid ODR violations, see N4381
68 template <class T> struct static_const { static const T value; };
69 template <class T> const T static_const<T>::value = T();
70
71 namespace {
72 static const impl::boost_test_print_type_impl& boost_test_print_type =
73 static_const<impl::boost_test_print_type_impl>::value;
74 }
75
76
77// ************************************************************************** //
78// ************** print_log_value ************** //
79// ************************************************************************** //
80
81template<typename T>
82struct print_log_value {
83 void operator()( std::ostream& ostr, T const& t )
84 {
85 typedef typename mpl::or_<is_array<T>,is_function<T>,is_abstract<T> >::type cant_use_nl;
86
87 std::streamsize old_precision = set_precision( ostr, cant_use_nl() );
88
89 //ostr << t;
90 using boost::test_tools::tt_detail::boost_test_print_type;
91 boost_test_print_type(ostr, t);
92
93 if( old_precision != (std::streamsize)-1 )
94 ostr.precision( prec: old_precision );
95 }
96
97 std::streamsize set_precision( std::ostream& ostr, mpl::false_ )
98 {
99 if( std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::radix == 2 )
100 return ostr.precision( 2 + std::numeric_limits<T>::digits * 301/1000 );
101 else if ( std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::radix == 10 ) {
102#ifdef BOOST_NO_CXX11_NUMERIC_LIMITS
103 // (was BOOST_NO_NUMERIC_LIMITS_LOWEST but now deprecated).
104 // No support for std::numeric_limits<double>::max_digits10,
105 // so guess that a couple of guard digits more than digits10 will display any difference.
106 return ostr.precision( 2 + std::numeric_limits<T>::digits10 );
107#else
108 // std::numeric_limits<double>::max_digits10; IS supported.
109 // Any noisy or guard digits needed to display any difference are included in max_digits10.
110 return ostr.precision( std::numeric_limits<T>::max_digits10 );
111#endif
112 }
113 // else if T is not specialized for std::numeric_limits<>,
114 // then will just get the default precision of 6 digits.
115 return (std::streamsize)-1;
116 }
117
118 std::streamsize set_precision( std::ostream&, mpl::true_ ) { return (std::streamsize)-1; }
119};
120
121//____________________________________________________________________________//
122
123#if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x564))
124template<typename T, std::size_t N >
125struct print_log_value< T[N] > {
126 void operator()( std::ostream& ostr, T const* t )
127 {
128 ostr << t;
129 }
130};
131#endif
132
133//____________________________________________________________________________//
134
135template<>
136struct BOOST_TEST_DECL print_log_value<bool> {
137 void operator()( std::ostream& ostr, bool t );
138};
139
140//____________________________________________________________________________//
141
142template<>
143struct BOOST_TEST_DECL print_log_value<char> {
144 void operator()( std::ostream& ostr, char t );
145};
146
147//____________________________________________________________________________//
148
149template<>
150struct BOOST_TEST_DECL print_log_value<unsigned char> {
151 void operator()( std::ostream& ostr, unsigned char t );
152};
153
154//____________________________________________________________________________//
155
156template<>
157struct BOOST_TEST_DECL print_log_value<char const*> {
158 void operator()( std::ostream& ostr, char const* t );
159};
160
161//____________________________________________________________________________//
162
163template<>
164struct BOOST_TEST_DECL print_log_value<wchar_t const*> {
165 void operator()( std::ostream& ostr, wchar_t const* t );
166};
167
168#if !defined(BOOST_NO_CXX11_NULLPTR)
169template<>
170struct print_log_value<std::nullptr_t> {
171 // declaration and definition is here because of #12969 https://svn.boost.org/trac10/ticket/12969
172 void operator()( std::ostream& ostr, std::nullptr_t /*t*/ ) {
173 ostr << "nullptr";
174 }
175};
176#endif
177
178//____________________________________________________________________________//
179
180// ************************************************************************** //
181// ************** print_helper ************** //
182// ************************************************************************** //
183// Adds level of indirection to the output operation, allowing us to customize
184// it for types that do not support operator << directly or for any other reason
185
186template<typename T>
187struct print_helper_t {
188 explicit print_helper_t( T const& t ) : m_t( t ) {}
189
190 T const& m_t;
191};
192
193//____________________________________________________________________________//
194
195#if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x564))
196// Borland suffers premature pointer decay passing arrays by reference
197template<typename T, std::size_t N >
198struct print_helper_t< T[N] > {
199 explicit print_helper_t( T const * t ) : m_t( t ) {}
200
201 T const * m_t;
202};
203#endif
204
205//____________________________________________________________________________//
206
207template<typename T>
208inline print_helper_t<T>
209print_helper( T const& t )
210{
211 return print_helper_t<T>( t );
212}
213
214//____________________________________________________________________________//
215
216template<typename T>
217inline std::ostream&
218operator<<( std::ostream& ostr, print_helper_t<T> const& ph )
219{
220 print_log_value<T>()( ostr, ph.m_t );
221
222 return ostr;
223}
224
225//____________________________________________________________________________//
226
227} // namespace tt_detail
228
229// ************************************************************************** //
230// ************** BOOST_TEST_DONT_PRINT_LOG_VALUE ************** //
231// ************************************************************************** //
232
233#define BOOST_TEST_DONT_PRINT_LOG_VALUE( the_type ) \
234namespace boost{ namespace test_tools{ namespace tt_detail{ \
235template<> \
236struct print_log_value<the_type > { \
237 void operator()( std::ostream&, the_type const& ) {} \
238}; \
239}}} \
240/**/
241
242} // namespace test_tools
243} // namespace boost
244
245#include <boost/test/detail/enable_warnings.hpp>
246
247#endif // BOOST_TEST_TOOLS_IMPL_COMMON_HPP_012705GER
248

source code of include/boost/test/tools/detail/print_helper.hpp