Add detail/is_range.hpp

2021-10-16 20:44:32 +03:00
parent 9bbedce029
commit 415f2fafe2
3 changed files with 155 additions and 0 deletions
@@ -0,0 +1,55 @@
+// Copyright 2017 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#ifndef BOOST_HASH_DETAIL_IS_RANGE_HPP_INCLUDED
+#define BOOST_HASH_DETAIL_IS_RANGE_HPP_INCLUDED
+
+#include <boost/type_traits/integral_constant.hpp>
+#include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/declval.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/core/enable_if.hpp>
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
+#include <iterator>
+
+namespace boost
+{
+namespace hash_detail
+{
+
+#if !defined(BOOST_NO_CXX11_DECLTYPE) && !defined(BOOST_NO_SFINAE_EXPR) && !BOOST_WORKAROUND(BOOST_GCC, < 40700)
+
+template<class It> true_type is_range_check( It first, It last, typename std::iterator_traits<It>::difference_type* = 0 );
+
+template<class T> decltype( is_range_check( declval<T const&>().begin(), declval<T const&>().end() ) ) is_range_( int );
+template<class T> false_type is_range_( ... );
+
+template<class T> struct is_range: decltype( is_range_<T>( 0 ) )
+{
+};
+
+#else
+
+template<class T, class E = true_type> struct is_range_: false_type
+{
+};
+
+template<class T> struct is_range_< T, integral_constant< bool,
+        is_same<typename T::value_type, typename std::iterator_traits<typename T::const_iterator>::value_type>::value &&
+        is_integral<typename T::size_type>::value
+    > >: true_type
+{
+};
+
+template<class T> struct is_range: is_range_<T>
+{
+};
+
+#endif // !defined(BOOST_NO_CXX11_DECLTYPE) && !defined(BOOST_NO_SFINAE_EXPR)
+
+} // namespace hash_detail
+} // namespace boost
+
+#endif // #ifndef BOOST_HASH_DETAIL_IS_RANGE_HPP_INCLUDED