From 2585d280d1e03ed5fdc09cdb4a58798713f6d26b Mon Sep 17 00:00:00 2001
From: cnugteren <cedric.nugteren@blippar.com>
Date: Thu, 12 Nov 2015 15:07:20 +0100
Subject: [PATCH 1/2] Added an optional absolute margin to the approximation
 checks

---
 include/internal/catch_approx.hpp | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/internal/catch_approx.hpp b/include/internal/catch_approx.hpp
index f5dba61a..5dd7df8e 100644
--- a/include/internal/catch_approx.hpp
+++ b/include/internal/catch_approx.hpp
@@ -20,12 +20,14 @@ namespace Detail {
     public:
         explicit Approx ( double value )
         :   m_epsilon( std::numeric_limits<float>::epsilon()*100 ),
+            m_margin( 0.0 ),
             m_scale( 1.0 ),
             m_value( value )
         {}
 
         Approx( Approx const& other )
         :   m_epsilon( other.m_epsilon ),
+            m_margin( other.m_margin ),
             m_scale( other.m_scale ),
             m_value( other.m_value )
         {}
@@ -37,13 +39,19 @@ namespace Detail {
         Approx operator()( double value ) {
             Approx approx( value );
             approx.epsilon( m_epsilon );
+            approx.margin( m_margin );
             approx.scale( m_scale );
             return approx;
         }
 
         friend bool operator == ( double lhs, Approx const& 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) ) );
+            auto relativeOK = fabs( lhs - rhs.m_value ) < rhs.m_epsilon * (rhs.m_scale + (std::max)( fabs(lhs), fabs(rhs.m_value) ) );
+            if ( relativeOK ) {
+                return true;
+            }
+            auto absoluteOK = fabs( lhs - rhs.m_value ) < rhs.m_margin;
+            return absoluteOK;
         }
 
         friend bool operator == ( Approx const& lhs, double rhs ) {
@@ -63,6 +71,11 @@ namespace Detail {
             return *this;
         }
 
+        Approx& margin( double newMargin ) {
+            m_margin = newMargin;
+            return *this;
+        }
+
         Approx& scale( double newScale ) {
             m_scale = newScale;
             return *this;
@@ -76,6 +89,7 @@ namespace Detail {
 
     private:
         double m_epsilon;
+        double m_margin;
         double m_scale;
         double m_value;
     };

From 3523c39f44c855c1d6f0d7ef3d3a3ea12d4a8987 Mon Sep 17 00:00:00 2001
From: CNugteren <web@cedricnugteren.nl>
Date: Thu, 12 Nov 2015 15:31:42 +0100
Subject: [PATCH 2/2] Changed 'auto' into 'bool' for C++98 compatibility

---
 include/internal/catch_approx.hpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/internal/catch_approx.hpp b/include/internal/catch_approx.hpp
index 5dd7df8e..08a15b71 100644
--- a/include/internal/catch_approx.hpp
+++ b/include/internal/catch_approx.hpp
@@ -46,11 +46,11 @@ namespace Detail {
 
         friend bool operator == ( double lhs, Approx const& rhs ) {
             // Thanks to Richard Harris for his help refining this formula
-            auto relativeOK = fabs( lhs - rhs.m_value ) < rhs.m_epsilon * (rhs.m_scale + (std::max)( fabs(lhs), fabs(rhs.m_value) ) );
+            bool relativeOK = fabs( lhs - rhs.m_value ) < rhs.m_epsilon * (rhs.m_scale + (std::max)( fabs(lhs), fabs(rhs.m_value) ) );
             if ( relativeOK ) {
                 return true;
             }
-            auto absoluteOK = fabs( lhs - rhs.m_value ) < rhs.m_margin;
+            bool absoluteOK = fabs( lhs - rhs.m_value ) < rhs.m_margin;
             return absoluteOK;
         }