Fix usage av::Rational with C++20 and newer applications

flowerlove · Sep 23, 2023 · 3849ca6 · 3849ca6
1 parent e9f7182
commit 3849ca6
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Showing 2 changed files with 35 additions and 54 deletions.
diff --git a/src/rational.cpp b/src/rational.cpp
@@ -84,66 +84,23 @@ double Rational::operator ()() const noexcept
     return av_q2d(m_value);
 }
 
-bool Rational::operator ==(const Rational &other) const noexcept
+int Rational::threewaycmp(const Rational &other) const noexcept
 {
     // HACK: in this case av_cmp_q() return INT_MIN;
     if (m_value.den == 0 &&
         m_value.num == 0 &&
         other.getDenominator() == 0 &&
         other.getNumerator()   == 0)
     {
-        return true;
+        return 0;
     }
-
-    return (av_cmp_q(m_value, other.getValue()) == 0 ? true : false);
-}
-
-#if __cplusplus > 201703L
-
-std::strong_ordering Rational::operator<=>(const Rational &other) const noexcept
-{
-    // HACK: in this case av_cmp_q() return INT_MIN;
-    if (m_value.den == 0 &&
-        m_value.num == 0 &&
-        other.getDenominator() == 0 &&
-        other.getNumerator()   == 0)
-    {
-        return std::strong_ordering::equal;
-    }
-    auto const result = av_cmp_q(m_value, other.getValue());
-    return result == 0 ? std::strong_ordering::equal :
-               result == -1 ? std::strong_ordering::less : std::strong_ordering::greater;
-}
-
-#else
-
-bool Rational::operator!=(const Rational &other) const noexcept
-{
-    return !(*this == other);
-}
-
-bool Rational::operator <(const Rational &other) const noexcept
-{
-    return (av_cmp_q(m_value, other.getValue()) == -1 ? true : false);
-}
-
-bool Rational::operator>(const Rational &other) const noexcept
-{
-    return (av_cmp_q(m_value, other.getValue()) == 1 ? true : false);
-}
-
-bool Rational::operator<=(const Rational &other) const noexcept
-{
     auto const result = av_cmp_q(m_value, other.getValue());
-    return *this == other || result == -1;
+    return result == 0 ? 0 : result == -1 ? -1 : 1;
 }
 
-bool Rational::operator>=(const Rational &other) const noexcept
+bool Rational::operator ==(const Rational &other) const noexcept
 {
-    auto const result = av_cmp_q(m_value, other.getValue());
-    return *this == other || result == 1;
+    return threewaycmp(other) == 0;
 }
 
-#endif
-
 } // ::av
diff --git a/src/rational.h b/src/rational.h
@@ -50,13 +50,34 @@ class Rational
 
     bool      operator== (const Rational   &other) const noexcept;
 #if __cplusplus > 201703L
-    std::strong_ordering operator<=>(const Rational &other) const noexcept;
+    std::strong_ordering operator<=>(const Rational &other) const noexcept
+    {
+        switch (threewaycmp(other)) {
+        case -1:
+            return std::strong_ordering::less;
+        case 0:
+            return std::strong_ordering::equal;
+        case 1:
+            return std::strong_ordering::greater;
+        }
+        return std::strong_ordering::equal; // make a compiler happy
+    }
 #else
-    bool      operator!= (const Rational   &other) const noexcept;
-    bool      operator<  (const Rational   &other) const noexcept;
-    bool      operator>  (const Rational   &other) const noexcept;
-    bool      operator<= (const Rational   &other) const noexcept;
-    bool      operator>= (const Rational   &other) const noexcept;
+    bool operator!= (const Rational &other) const noexcept {
+        return threewaycmp(other) != 0;
+    }
+    bool operator<(const Rational &other) const noexcept {
+        return threewaycmp(other) < 0;
+    }
+    bool operator>(const Rational &other) const noexcept {
+        return threewaycmp(other) > 0;
+    }
+    bool operator<=(const Rational &other) const noexcept {
+        return (*this < other) || (*this == other);
+    }
+    bool operator>=(const Rational &other) const noexcept {
+        return (*this > other) || (*this == other);
+    }
 #endif
 
     Rational  operator+  (const Rational   &value) const noexcept;
@@ -71,6 +92,9 @@ class Rational
         return m_value;
     }
 
+private:
+    int threewaycmp(const Rational &other) const noexcept;
+
 private:
     AVRational m_value;
 };