using std:: ptrdiff_t, size_t moved from range_traits.h

size_t needed by allocator

auxi/core_util.h

@@ -63,6 +63,10 @@
 namespace oel
 {
 
+using std::ptrdiff_t;
+using std::size_t;
+
+
 //! Declare an overload to declare a type trivially relocatable. See is_trivially_relocatable
 template< typename T >
 bool_constant< std::is_trivially_move_constructible_v<T> and std::is_trivially_destructible_v<T> >

auxi/range_traits.h

@@ -53,10 +53,6 @@ namespace _detail
 }
 
 
-using std::ptrdiff_t;
-using std::size_t;
-
-
 using std::begin;  using std::end;