include/catch2/catch_approx.hpp

0001
0002 //              Copyright Catch2 Authors
0003 // Distributed under the Boost Software License, Version 1.0.
0004 //   (See accompanying file LICENSE.txt or copy at
0005 //        https://www.boost.org/LICENSE_1_0.txt)
0006
0007 // SPDX-License-Identifier: BSL-1.0
0008 #ifndef CATCH_APPROX_HPP_INCLUDED
0009 #define CATCH_APPROX_HPP_INCLUDED
0010
0011 #include <catch2/catch_tostring.hpp>
0012
0013 #include <type_traits>
0014
0015 namespace Catch {
0016
0017     class Approx {
0018     private:
0019         bool equalityComparisonImpl(double other) const;
0020         // Sets and validates the new margin (margin >= 0)
0021         void setMargin(double margin);
0022         // Sets and validates the new epsilon (0 < epsilon < 1)
0023         void setEpsilon(double epsilon);
0024
0025     public:
0026         explicit Approx ( double value );
0027
0028         static Approx custom();
0029
0030         Approx operator-() const;
0031
0032         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0033         Approx operator()( T const& value ) const {
0034             Approx approx( static_cast<double>(value) );
0035             approx.m_epsilon = m_epsilon;
0036             approx.m_margin = m_margin;
0037             approx.m_scale = m_scale;
0038             return approx;
0039         }
0040
0041         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0042         explicit Approx( T const& value ): Approx(static_cast<double>(value))
0043         {}
0044
0045
0046         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0047         friend bool operator == ( const T& lhs, Approx const& rhs ) {
0048             auto lhs_v = static_cast<double>(lhs);
0049             return rhs.equalityComparisonImpl(lhs_v);
0050         }
0051
0052         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0053         friend bool operator == ( Approx const& lhs, const T& rhs ) {
0054             return operator==( rhs, lhs );
0055         }
0056
0057         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0058         friend bool operator != ( T const& lhs, Approx const& rhs ) {
0059             return !operator==( lhs, rhs );
0060         }
0061
0062         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0063         friend bool operator != ( Approx const& lhs, T const& rhs ) {
0064             return !operator==( rhs, lhs );
0065         }
0066
0067         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0068         friend bool operator <= ( T const& lhs, Approx const& rhs ) {
0069             return static_cast<double>(lhs) < rhs.m_value || lhs == rhs;
0070         }
0071
0072         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0073         friend bool operator <= ( Approx const& lhs, T const& rhs ) {
0074             return lhs.m_value < static_cast<double>(rhs) || lhs == rhs;
0075         }
0076
0077         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0078         friend bool operator >= ( T const& lhs, Approx const& rhs ) {
0079             return static_cast<double>(lhs) > rhs.m_value || lhs == rhs;
0080         }
0081
0082         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0083         friend bool operator >= ( Approx const& lhs, T const& rhs ) {
0084             return lhs.m_value > static_cast<double>(rhs) || lhs == rhs;
0085         }
0086
0087         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0088         Approx& epsilon( T const& newEpsilon ) {
0089             const auto epsilonAsDouble = static_cast<double>(newEpsilon);
0090             setEpsilon(epsilonAsDouble);
0091             return *this;
0092         }
0093
0094         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0095         Approx& margin( T const& newMargin ) {
0096             const auto marginAsDouble = static_cast<double>(newMargin);
0097             setMargin(marginAsDouble);
0098             return *this;
0099         }
0100
0101         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
0102         Approx& scale( T const& newScale ) {
0103             m_scale = static_cast<double>(newScale);
0104             return *this;
0105         }
0106
0107         std::string toString() const;
0108
0109     private:
0110         double m_epsilon;
0111         double m_margin;
0112         double m_scale;
0113         double m_value;
0114     };
0115
0116 namespace literals {
0117     Approx operator ""_a(long double val);
0118     Approx operator ""_a(unsigned long long val);
0119 } // end namespace literals
0120
0121 template<>
0122 struct StringMaker<Catch::Approx> {
0123     static std::string convert(Catch::Approx const& value);
0124 };
0125
0126 } // end namespace Catch
0127
0128 #endif // CATCH_APPROX_HPP_INCLUDED