message: Making comparison operators const.
diff: @@ -7897,14 +7897,14 @@ class basic_json
  /// equal operator (calls key())
  template<typename KeyType>
  - bool operator==(const KeyType& key)
  + bool operator==(const KeyType& key) const
  {
  return proxy.key() == key;
  }
  /// not equal operator (calls key())
  template<typename KeyType>
  - bool operator!=(const KeyType& key)
  + bool operator!=(const KeyType& key) const
  {
  return proxy.key() != key;
  }
  @@ -7930,14 +7930,14 @@ class basic_json
  /// equal operator (calls value())
  template<typename ValueType>
  - bool operator==(const ValueType& value)
  + bool operator==(const ValueType& value) const
  {
  return proxy.value() == value;
  }
  /// not equal operator (calls value())
  template<typename ValueType>
  - bool operator!=(const ValueType& value)
  + bool operator!=(const ValueType& value) const
  {
  return proxy.value() != value;
  }
  