Approx cleanup: More tests, INFINITY handling, etc

This commit is contained in:
Martin Hořeňovský
2017-11-01 07:30:11 +01:00
parent 00af677577
commit 22ac9d2184
8 changed files with 207 additions and 45 deletions

View File

@@ -8,18 +8,22 @@
#include "catch_approx.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 {
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 ),
@@ -37,6 +41,12 @@ namespace Detail {
return oss.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)));
}
} // end namespace Detail
std::string StringMaker<Catch::Detail::Approx>::convert(Catch::Detail::Approx const& value) {

View File

@@ -11,16 +11,15 @@
#include "catch_enforce.h"
#include "catch_tostring.h"
#include <cmath>
#include <type_traits>
namespace Catch {
namespace Detail {
double dmax(double lhs, double rhs);
class Approx {
private:
bool equalityComparisonImpl(double other) const;
public:
explicit Approx ( double value );
@@ -42,15 +41,8 @@ namespace Detail {
template <typename T, typename = typename std::enable_if<std::is_constructible<double, T>::value>::type>
friend bool operator == ( const T& lhs, Approx const& rhs ) {
// Thanks to Richard Harris for his help refining this formula
auto lhs_v = static_cast<double>(lhs);
bool relativeOK = std::fabs( lhs_v - rhs.m_value ) < rhs.m_epsilon * (rhs.m_scale + std::fabs(rhs.m_value) );
if (relativeOK) {
return true;
}
return std::fabs(lhs_v - rhs.m_value) <= rhs.m_margin;
return rhs.equalityComparisonImpl(lhs_v);
}
template <typename T, typename = typename std::enable_if<std::is_constructible<double, T>::value>::type>
@@ -90,18 +82,21 @@ namespace Detail {
template <typename T, typename = typename std::enable_if<std::is_constructible<double, T>::value>::type>
Approx& epsilon( T const& newEpsilon ) {
double asDouble = static_cast<double>(newEpsilon);
CATCH_ENFORCE(asDouble >= 0 && asDouble <= 1.0,
"Invalid Approx::epsilon: " << m_epsilon <<
", Approx::epsilon has to be between 0 and 1");
m_epsilon = asDouble;
double epsilonAsDouble = static_cast<double>(newEpsilon);
CATCH_ENFORCE(epsilonAsDouble >= 0 && epsilonAsDouble <= 1.0,
"Invalid Approx::epsilon: " << epsilonAsDouble
<< ", Approx::epsilon has to be between 0 and 1");
m_epsilon = epsilonAsDouble;
return *this;
}
template <typename T, typename = typename std::enable_if<std::is_constructible<double, T>::value>::type>
Approx& margin( T const& newMargin ) {
m_margin = static_cast<double>(newMargin);
CATCH_ENFORCE(m_margin >= 0, "Invalid Approx::margin: " << m_margin << ", Approx::Margin has to be non-negative.");
double marginAsDouble = static_cast<double>(newMargin);
CATCH_ENFORCE(marginAsDouble >= 0,
"Invalid Approx::margin: " << marginAsDouble
<< ", Approx::Margin has to be non-negative.");
m_margin = marginAsDouble;
return *this;
}