test/utils/lazy_ostream.hpp

0001 //  (C) Copyright Gennadiy Rozental 2001.
0002 //  Distributed under the Boost Software License, Version 1.0.
0003 //  (See accompanying file LICENSE_1_0.txt or copy at
0004 //  http://www.boost.org/LICENSE_1_0.txt)
0005
0006 //  See http://www.boost.org/libs/test for the library home page.
0007 //
0008 //  Description : contains definition for all test tools in test toolbox
0009 // ***************************************************************************
0010
0011 #ifndef BOOST_TEST_UTILS_LAZY_OSTREAM_HPP
0012 #define BOOST_TEST_UTILS_LAZY_OSTREAM_HPP
0013
0014 // Boost.Test
0015 #include <boost/test/detail/config.hpp>
0016 #include <boost/test/tools/detail/print_helper.hpp>
0017
0018 // STL
0019 #include <iosfwd>
0020
0021 #include <boost/test/detail/suppress_warnings.hpp>
0022
0023 //____________________________________________________________________________//
0024
0025 // ************************************************************************** //
0026 // **************                  lazy_ostream                ************** //
0027 // ************************************************************************** //
0028
0029 namespace boost {
0030 namespace unit_test {
0031
0032 class BOOST_TEST_DECL lazy_ostream {
0033 public:
0034     virtual                 ~lazy_ostream()                                         {}
0035
0036     static lazy_ostream&    instance()                                              { return inst; }
0037
0038     #if !defined(BOOST_EMBTC)
0039
0040     friend std::ostream&    operator<<( std::ostream& ostr, lazy_ostream const& o ) { return o( ostr ); }
0041
0042     #else
0043
0044     friend std::ostream&    operator<<( std::ostream& ostr, lazy_ostream const& o );
0045
0046     #endif
0047
0048     // access method
0049     bool                    empty() const                                           { return m_empty; }
0050
0051     // actual printing interface; to be accessed only by this class and children
0052     virtual std::ostream&   operator()( std::ostream& ostr ) const                  { return ostr; }
0053 protected:
0054     explicit                lazy_ostream( bool p_empty = true ) : m_empty( p_empty )    {}
0055
0056 private:
0057     // Data members
0058     bool                    m_empty;
0059     static lazy_ostream     inst;
0060 };
0061
0062 #if defined(BOOST_EMBTC)
0063
0064     inline std::ostream&    operator<<( std::ostream& ostr, lazy_ostream const& o ) { return o( ostr ); }
0065
0066 #endif
0067
0068 //____________________________________________________________________________//
0069
0070 template<typename PrevType, typename T, typename StorageT=T const&>
0071 class lazy_ostream_impl : public lazy_ostream {
0072 public:
0073     lazy_ostream_impl( PrevType const& prev, T const& value )
0074     : lazy_ostream( false )
0075     , m_prev( prev )
0076     , m_value( value )
0077     {
0078     }
0079
0080     std::ostream&   operator()( std::ostream& ostr ) const BOOST_OVERRIDE
0081     {
0082         return m_prev(ostr) << test_tools::tt_detail::print_helper(m_value);
0083     }
0084 private:
0085     // Data members
0086     PrevType const&         m_prev;
0087     StorageT                m_value;
0088 };
0089
0090 //____________________________________________________________________________//
0091
0092 template<typename T>
0093 inline lazy_ostream_impl<lazy_ostream,T>
0094 operator<<( lazy_ostream const& prev, T const& v )
0095 {
0096     return lazy_ostream_impl<lazy_ostream,T>( prev, v );
0097 }
0098
0099 //____________________________________________________________________________//
0100
0101 template<typename PrevPrevType, typename TPrev, typename T>
0102 inline lazy_ostream_impl<lazy_ostream_impl<PrevPrevType,TPrev>,T>
0103 operator<<( lazy_ostream_impl<PrevPrevType,TPrev> const& prev, T const& v )
0104 {
0105     typedef lazy_ostream_impl<PrevPrevType,TPrev> PrevType;
0106     return lazy_ostream_impl<PrevType,T>( prev, v );
0107 }
0108
0109 //____________________________________________________________________________//
0110
0111 #if BOOST_TEST_USE_STD_LOCALE
0112
0113 template<typename R,typename S>
0114 inline lazy_ostream_impl<lazy_ostream,R& (BOOST_TEST_CALL_DECL *)(S&),R& (BOOST_TEST_CALL_DECL *)(S&)>
0115 operator<<( lazy_ostream const& prev, R& (BOOST_TEST_CALL_DECL *man)(S&) )
0116 {
0117     typedef R& (BOOST_TEST_CALL_DECL * ManipType)(S&);
0118
0119     return lazy_ostream_impl<lazy_ostream,ManipType,ManipType>( prev, man );
0120 }
0121
0122 //____________________________________________________________________________//
0123
0124 template<typename PrevPrevType, typename TPrev,typename R,typename S>
0125 inline lazy_ostream_impl<lazy_ostream_impl<PrevPrevType,TPrev>,R& (BOOST_TEST_CALL_DECL *)(S&),R& (BOOST_TEST_CALL_DECL *)(S&)>
0126 operator<<( lazy_ostream_impl<PrevPrevType,TPrev> const& prev, R& (BOOST_TEST_CALL_DECL *man)(S&) )
0127 {
0128     typedef R& (BOOST_TEST_CALL_DECL * ManipType)(S&);
0129
0130     return lazy_ostream_impl<lazy_ostream_impl<PrevPrevType,TPrev>,ManipType,ManipType>( prev, man );
0131 }
0132
0133 //____________________________________________________________________________//
0134
0135 #endif
0136
0137 #define BOOST_TEST_LAZY_MSG( M ) (::boost::unit_test::lazy_ostream::instance() << M)
0138
0139 } // namespace unit_test
0140 } // namespace boost
0141
0142 #include <boost/test/detail/enable_warnings.hpp>
0143
0144 #endif // BOOST_TEST_UTILS_LAZY_OSTREAM_HPP