1 /*
2  *  Created by Martin on 07/11/2017.
3  *
4  * Distributed under the Boost Software License, Version 1.0. (See accompanying
5  * file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6  */
7 #ifndef TWOBLUECUBES_CATCH_MATCHERS_FLOATING_H_INCLUDED
8 #define TWOBLUECUBES_CATCH_MATCHERS_FLOATING_H_INCLUDED
9 
10 #include "catch_matchers.h"
11 
12 namespace Catch {
13 namespace Matchers {
14 
15     namespace Floating {
16 
17         enum class FloatingPointKind : uint8_t;
18 
19         struct WithinAbsMatcher : MatcherBase<double> {
20             WithinAbsMatcher(double target, double margin);
21             bool match(double const& matchee) const override;
22             std::string describe() const override;
23         private:
24             double m_target;
25             double m_margin;
26         };
27 
28         struct WithinUlpsMatcher : MatcherBase<double> {
29             WithinUlpsMatcher(double target, uint64_t ulps, FloatingPointKind baseType);
30             bool match(double const& matchee) const override;
31             std::string describe() const override;
32         private:
33             double m_target;
34             uint64_t m_ulps;
35             FloatingPointKind m_type;
36         };
37 
38         // Given IEEE-754 format for floats and doubles, we can assume
39         // that float -> double promotion is lossless. Given this, we can
40         // assume that if we do the standard relative comparison of
41         // |lhs - rhs| <= epsilon * max(fabs(lhs), fabs(rhs)), then we get
42         // the same result if we do this for floats, as if we do this for
43         // doubles that were promoted from floats.
44         struct WithinRelMatcher : MatcherBase<double> {
45             WithinRelMatcher(double target, double epsilon);
46             bool match(double const& matchee) const override;
47             std::string describe() const override;
48         private:
49             double m_target;
50             double m_epsilon;
51         };
52 
53     } // namespace Floating
54 
55     // The following functions create the actual matcher objects.
56     // This allows the types to be inferred
57     Floating::WithinUlpsMatcher WithinULP(double target, uint64_t maxUlpDiff);
58     Floating::WithinUlpsMatcher WithinULP(float target, uint64_t maxUlpDiff);
59     Floating::WithinAbsMatcher WithinAbs(double target, double margin);
60     Floating::WithinRelMatcher WithinRel(double target, double eps);
61     // defaults epsilon to 100*numeric_limits<double>::epsilon()
62     Floating::WithinRelMatcher WithinRel(double target);
63     Floating::WithinRelMatcher WithinRel(float target, float eps);
64     // defaults epsilon to 100*numeric_limits<float>::epsilon()
65     Floating::WithinRelMatcher WithinRel(float target);
66 
67 } // namespace Matchers
68 } // namespace Catch
69 
70 #endif // TWOBLUECUBES_CATCH_MATCHERS_FLOATING_H_INCLUDED
71