Move std::complex support to hash.hpp

include/boost/container_hash/extensions.hpp

@@ -21,7 +21,6 @@
 #include <boost/container_hash/hash.hpp>
 #include <boost/core/enable_if.hpp>
 #include <boost/static_assert.hpp>
-#include <complex>
 
 #if !defined(BOOST_NO_CXX11_HDR_TUPLE)
 # include <tuple>
@@ -36,9 +35,6 @@ namespace boost
     template <class A, class B>
     std::size_t hash_value(std::pair<A, B> const&);
 
-    template <class T>
-    std::size_t hash_value(std::complex<T> const&);
-
     template <class A, class B>
     std::size_t hash_value(std::pair<A, B> const& v)
     {
@@ -48,15 +44,6 @@ namespace boost
         return seed;
     }
 
-    template <class T>
-    std::size_t hash_value(std::complex<T> const& v)
-    {
-        boost::hash<T> hasher;
-        std::size_t seed = hasher(v.imag());
-        seed ^= hasher(v.real()) + (seed<<6) + (seed>>2);
-        return seed;
-    }
-
 #if !defined(BOOST_NO_CXX11_HDR_TUPLE)
     namespace hash_detail {
         template <std::size_t I, typename T>

include/boost/container_hash/hash.hpp

@@ -30,6 +30,7 @@
 #include <boost/cstdint.hpp>
 #include <iterator>
 #include <string>
+#include <complex>
 #include <climits>
 
 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
@@ -153,6 +154,19 @@ namespace boost
         return boost::hash_range( x, x + N );
     }
 
+    // complex
+
+    template <class T>
+    std::size_t hash_value( std::complex<T> const& v )
+    {
+        std::size_t seed = 0;
+
+        boost::hash_combine( seed, v.real() );
+        boost::hash_combine( seed, v.imag() );
+
+        return seed;
+    }
+
     // ranges (list, set, deque...)
 
     template <typename T>