catch2/include/internal/catch_approx.cpp
2019-04-18 15:30:38 +02:00

88 lines
2.5 KiB
C++

/*
* Created by Martin on 19/07/2017.
* Copyright 2017 Two Blue Cubes Ltd. All rights reserved.
*
* Distributed under the Boost Software License, Version 1.0. (See accompanying
* file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#include "catch_approx.h"
#include "catch_enforce.h"
#include <cmath>
#include <limits>
namespace {
// Performs equivalent check of std::fabs(lhs - rhs) <= margin
// But without the subtraction to allow for INFINITY in comparison
bool marginComparison(double lhs, double rhs, double margin) {
return (lhs + margin >= rhs) && (rhs + margin >= lhs);
}
}
namespace Catch {
namespace Detail {
Approx::Approx ( double value )
: m_epsilon( std::numeric_limits<float>::epsilon()*100 ),
m_margin( 0.0 ),
m_scale( 0.0 ),
m_value( value )
{}
Approx Approx::custom() {
return Approx( 0 );
}
Approx Approx::operator-() const {
auto temp(*this);
temp.m_value = -temp.m_value;
return temp;
}
std::string Approx::toString() const {
ReusableStringStream rss;
rss << "Approx( " << ::Catch::Detail::stringify( m_value ) << " )";
return rss.str();
}
bool Approx::equalityComparisonImpl(const double other) const {
// First try with fixed margin, then compute margin based on epsilon, scale and Approx's value
// Thanks to Richard Harris for his help refining the scaled margin value
return marginComparison(m_value, other, m_margin) || marginComparison(m_value, other, m_epsilon * (m_scale + std::fabs(m_value)));
}
void Approx::setMargin(double newMargin) {
CATCH_ENFORCE(newMargin >= 0,
"Invalid Approx::margin: " << newMargin << '.'
<< " Approx::Margin has to be non-negative.");
m_margin = newMargin;
}
void Approx::setEpsilon(double newEpsilon) {
CATCH_ENFORCE(newEpsilon >= 0 && newEpsilon <= 1.0,
"Invalid Approx::epsilon: " << newEpsilon << '.'
<< " Approx::epsilon has to be in [0, 1]");
m_epsilon = newEpsilon;
}
} // end namespace Detail
namespace literals {
Detail::Approx operator "" _a(long double val) {
return Detail::Approx(val);
}
Detail::Approx operator "" _a(unsigned long long val) {
return Detail::Approx(val);
}
} // end namespace literals
std::string StringMaker<Catch::Detail::Approx>::convert(Catch::Detail::Approx const& value) {
return value.toString();
}
} // end namespace Catch