Catch/include/internal/catch_approx.hpp
2012-05-15 07:42:26 +01:00

92 lines
2.5 KiB
C++

/*
* Created by Phil on 28/04/2011.
* Copyright 2010 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)
*/
#ifndef TWOBLUECUBES_CATCH_APPROX_HPP_INCLUDED
#define TWOBLUECUBES_CATCH_APPROX_HPP_INCLUDED
#include "catch_capture.hpp"
#include <cmath>
#include <limits>
namespace Catch {
namespace Detail {
class Approx {
public:
explicit Approx ( double value )
: m_epsilon( std::numeric_limits<float>::epsilon()*100 ),
m_scale( 1.0 ),
m_value( value )
{}
Approx( const Approx& other )
: m_epsilon( other.m_epsilon ),
m_scale( other.m_scale ),
m_value( other.m_value )
{}
static Approx custom() {
return Approx( 0 );
}
Approx operator()( double value ) {
Approx approx( value );
approx.epsilon( m_epsilon );
approx.scale( m_scale );
return approx;
}
friend bool operator == ( double lhs, const Approx& rhs ) {
// Thanks to Richard Harris for his help refining this formula
return fabs( lhs - rhs.m_value ) < rhs.m_epsilon * (rhs.m_scale + (std::max)( fabs(lhs), fabs(rhs.m_value) ) );
}
friend bool operator == ( const Approx& lhs, double rhs ) {
return operator==( rhs, lhs );
}
friend bool operator != ( double lhs, const Approx& rhs ) {
return !operator==( lhs, rhs );
}
friend bool operator != ( const Approx& lhs, double rhs ) {
return !operator==( rhs, lhs );
}
Approx& epsilon( double newEpsilon ) {
m_epsilon = newEpsilon;
return *this;
}
Approx& scale( double newScale ) {
m_scale = newScale;
return *this;
}
std::string toString() const {
std::ostringstream oss;
oss << "Approx( " << m_value << ")";
return oss.str();
}
private:
double m_epsilon;
double m_scale;
double m_value;
};
}
template<>
inline std::string toString<Detail::Approx>( const Detail::Approx& value ) {
return value.toString();
}
} // end namespace Catch
#endif // TWOBLUECUBES_CATCH_APPROX_HPP_INCLUDED