For swap use ADL instead of specializing std::swap

src/lib/math/bigint/bigint.h

@@ -171,6 +171,8 @@ class BOTAN_PUBLIC_API(2, 0) BigInt final {
  std::swap(m_signedness, other.m_signedness);
  }
 
+ friend void swap(BigInt& x, BigInt& y) { x.swap(y); }
+
  void swap_reg(secure_vector<word>& reg) {
  m_data.swap(reg);
  // sign left unchanged
@@ -1034,13 +1036,4 @@ BOTAN_PUBLIC_API(2, 0) std::istream& operator>>(std::istream&, BigInt&);
 
 } // namespace Botan
 
-namespace std {
-
-template <>
-inline void swap<Botan::BigInt>(Botan::BigInt& x, Botan::BigInt& y) {
- x.swap(y);
-}
-
-} // namespace std
-
 #endif

src/lib/pubkey/ec_group/curve_gfp.h

@@ -179,6 +179,8 @@ class BOTAN_UNSTABLE_API CurveGFp final {
 
  void swap(CurveGFp& other) { std::swap(m_repr, other.m_repr); }
 
+ friend void swap(CurveGFp& x, CurveGFp& y) { x.swap(y); }
+
  /**
  * Equality operator
  * @param other a curve
@@ -204,13 +206,4 @@ inline bool operator!=(const CurveGFp& lhs, const CurveGFp& rhs) {
 
 } // namespace Botan
 
-namespace std {
-
-template <>
-inline void swap<Botan::CurveGFp>(Botan::CurveGFp& curve1, Botan::CurveGFp& curve2) noexcept {
- curve1.swap(curve2);
-}
-
-} // namespace std
-
 #endif

src/lib/pubkey/ec_group/ec_point.h

@@ -189,6 +189,8 @@ class BOTAN_PUBLIC_API(2, 0) EC_Point final {
  */
  void swap(EC_Point& other);
 
+ friend void swap(EC_Point& x, EC_Point& y) { x.swap(y); }
+
  /**
  * Randomize the point representation
  * The actual value (get_affine_x, get_affine_y) does not change
@@ -401,13 +403,4 @@ typedef EC_Point PointGFp;
 
 } // namespace Botan
 
-namespace std {
-
-template <>
-inline void swap<Botan::EC_Point>(Botan::EC_Point& x, Botan::EC_Point& y) {
- x.swap(y);
-}
-
-} // namespace std
-
 #endif