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
29namespace boost {
30namespace test_tools {
31
32// ************************************************************************** //
33// ************** bitwise comparison manipulator ************** //
34// ************************************************************************** //
35
36//! Bitwise comparison manipulator
37//! This is a terminal for the expression
38struct bitwise {};
39
40//____________________________________________________________________________//
41
42inline unit_test::lazy_ostream &
43operator<<( unit_test::lazy_ostream &o, bitwise ) { return o; }
44
45// needed for the lazy evaluation in lazy_ostream as bitwise is a terminal
46inline std::ostream&
47operator<<( std::ostream& o, bitwise ) { return o; }
48
49
50//____________________________________________________________________________//
51
52namespace 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 */
59template<typename Lhs, typename Rhs, typename E>
60inline assertion_result
61bitwise_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.
106template<typename T1, typename T2, typename T3, typename T4>
107inline assertion_result
108operator<<(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
115inline assertion_type
116operator<<( 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

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