catch2/include/internal/catch_approx.hpp
2011-06-06 08:21:21 +01:00

158 lines
4.4 KiB
C++

/*
* catch_approx.hpp
* Catch
*
* 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