approx.cc

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#include "tests/approx.h"
 
namespace
{
    // Performs equivalent check of std::fabs(lhs - rhs) <= margin
    // But without the subtraction to allow for INFINITY in comparison
    bool
    margin_comparison(float lhs, float rhs, float margin)
    {
        return (lhs + margin >= rhs) && (rhs + margin >= lhs);
    }
}
 
 
namespace eu::tests
{
    template <>
    bool
    is_approximately_equal
    (
        float const& lhs,
        float const& rhs,
        const ApproxData& data
    )
    {
        const auto m_value = lhs;
        const auto other = rhs;
        const auto m_epsilon = data.epsilon;
        const auto m_margin = data.margin;
        const auto m_scale = data.scale;
 
        // implementation:
 
        // 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
            margin_comparison(m_value, other, m_margin)
            ||
            margin_comparison
            (
                m_value,
                other,
                m_epsilon * (m_scale + std::fabs(m_value))
            )
            ;
    }
}