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
9 //! Bitwise comparison manipulator implementation
10 // ***************************************************************************
11
12 #ifndef BOOST_TEST_TOOLS_DETAIL_BITWISE_MANIP_HPP_012705GER
13 #define BOOST_TEST_TOOLS_DETAIL_BITWISE_MANIP_HPP_012705GER
14
15 // Boost Test
16 #include <boost/test/tools/detail/fwd.hpp>
17 #include <boost/test/tools/detail/indirections.hpp>
18
19 #include <boost/test/tools/assertion_result.hpp>
20 #include <boost/test/tools/assertion.hpp>
21
22 // STL
23 #include <climits> // for CHAR_BIT
24
25 #include <boost/test/detail/suppress_warnings.hpp>
26
27 //____________________________________________________________________________//
28
29 namespace boost {
30 namespace test_tools {
31
32 // ************************************************************************** //
33 // ************** bitwise comparison manipulator ************** //
34 // ************************************************************************** //
35
36 //! Bitwise comparison manipulator
37 //! This is a terminal for the expression
38 struct bitwise {};
39
40 //____________________________________________________________________________//
41
42 inline unit_test::lazy_ostream &
operator <<(unit_test::lazy_ostream & o,bitwise)43 operator<<( unit_test::lazy_ostream &o, bitwise ) { return o; }
44
45 // needed for the lazy evaluation in lazy_ostream as bitwise is a terminal
46 inline std::ostream&
operator <<(std::ostream & o,bitwise)47 operator<<( std::ostream& o, bitwise ) { return o; }
48
49
50 //____________________________________________________________________________//
51
52 namespace tt_detail {
53
54 /*!@brief Bitwise comparison of two operands
55 *
56 * This class constructs an @ref assertion_result that contains precise bit comparison information.
57 * In particular the location of the mismatches (if any) are printed in the assertion result.
58 */
59 template<typename Lhs, typename Rhs, typename E>
60 inline assertion_result
bitwise_compare(Lhs const & lhs,Rhs const & rhs,E const & expr)61 bitwise_compare(Lhs const& lhs, Rhs const& rhs, E const& expr )
62 {
63 assertion_result pr( true );
64
65 std::size_t left_bit_size = sizeof(Lhs)*CHAR_BIT;
66 std::size_t right_bit_size = sizeof(Rhs)*CHAR_BIT;
67
68 static Lhs const leftOne( 1 );
69 static Rhs const rightOne( 1 );
70
71 std::size_t total_bits = left_bit_size < right_bit_size ? left_bit_size : right_bit_size;
72
73 for( std::size_t counter = 0; counter < total_bits; ++counter ) {
74 if( (lhs & ( leftOne << counter )) != (rhs & (rightOne << counter)) ) {
75 if( pr ) {
76 pr.message() << " [";
77 expr.report( pr.message().stream() );
78 pr.message() << "]. Bitwise comparison failed";
79 pr = false;
80 }
81 pr.message() << "\nMismatch at position " << counter;
82 }
83 }
84
85 if( left_bit_size != right_bit_size ) {
86 if( pr ) {
87 pr.message() << " [";
88 expr.report( pr.message().stream() );
89 pr.message() << "]. Bitwise comparison failed";
90 pr = false;
91 }
92 pr.message() << "\nOperands bit sizes mismatch: " << left_bit_size << " != " << right_bit_size;
93 }
94
95 return pr;
96 }
97
98 //____________________________________________________________________________//
99
100 //! Returns an assertion_result using the bitwise comparison out of an expression
101 //!
102 //! This is used as a modifer of the normal operator<< on expressions to use the
103 //! bitwise comparison.
104 //!
105 //! @note Available only for compilers supporting the @c auto declaration.
106 template<typename T1, typename T2, typename T3, typename T4>
107 inline assertion_result
operator <<(assertion_evaluate_t<assertion::binary_expr<T1,T2,assertion::op::EQ<T3,T4>>> const & ae,bitwise)108 operator<<(assertion_evaluate_t<assertion::binary_expr<T1,T2,assertion::op::EQ<T3,T4> > > const& ae, bitwise )
109 {
110 return bitwise_compare( ae.m_e.lhs().value(), ae.m_e.rhs(), ae.m_e );
111 }
112
113 //____________________________________________________________________________//
114
115 inline assertion_type
operator <<(assertion_type const &,bitwise)116 operator<<( assertion_type const& , bitwise )
117 {
118 return assertion_type(CHECK_BUILT_ASSERTION);
119 }
120
121 //____________________________________________________________________________//
122
123 } // namespace tt_detail
124 } // namespace test_tools
125 } // namespace boost
126
127 #include <boost/test/detail/enable_warnings.hpp>
128
129 #endif // BOOST_TEST_TOOLS_DETAIL_BITWISE_MANIP_HPP_012705GER
130