catch2/include/internal/catch_approx.cpp
Pfiffikus 00af677577 Approx rework: default scale == 0, epsilon applies to Approx::value
Also adds check to Approx::epsilon that the new epsilon has a valid
(ie one between 0 and 1)

Based on
http://realtimecollisiondetection.net/blog/?p=89
https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
https://en.wikipedia.org/wiki/Approximation_error#Formal_Definition

The given epsilon should refer to the target value, otherwise
the result would be unexpected, e.g. 101.02 == Approx(100).epsilon(0.01)
is true.
The default scale should be invisible, thus,
e.g. 101.01 == Approx(100).epsilon(0.01) gets false.
Finally even 101.000001 == Approx(100).epsilon(0.01) is false
2017-10-31 15:43:42 +01:00

47 lines
1.1 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 <limits>
namespace Catch {
namespace Detail {
double dmax(double lhs, double rhs) {
if (lhs < rhs) {
return rhs;
}
return lhs;
}
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 );
}
std::string Approx::toString() const {
std::ostringstream oss;
oss << "Approx( " << ::Catch::Detail::stringify( m_value ) << " )";
return oss.str();
}
} // end namespace Detail
std::string StringMaker<Catch::Detail::Approx>::convert(Catch::Detail::Approx const& value) {
return value.toString();
}
} // end namespace Catch