整理

include/boost/iterator/interoperable.hpp

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+// (C) Copyright David Abrahams 2002.
+// (C) Copyright Jeremy Siek    2002.
+// (C) Copyright Thomas Witt    2002.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_INTEROPERABLE_23022003THW_HPP
+#define BOOST_INTEROPERABLE_23022003THW_HPP
+
+#include <type_traits>
+#include <boost/iterator/detail/type_traits/disjunction.hpp>
+
+namespace boost {
+namespace iterators {
+
+//
+// Meta function that determines whether two
+// iterator types are considered interoperable.
+//
+// Two iterator types A,B are considered interoperable if either
+// A is convertible to B or vice versa.
+// This interoperability definition is in sync with the
+// standards requirements on constant/mutable container
+// iterators (23.1 [lib.container.requirements]).
+//
+// For compilers that don't support is_convertible
+// is_interoperable gives false positives. See comments
+// on operator implementation for consequences.
+//
+template< typename A, typename B >
+struct is_interoperable :
+    public detail::disjunction< std::is_convertible< A, B >, std::is_convertible< B, A > >
+{
+};
+
+} // namespace iterators
+
+using iterators::is_interoperable;
+
+} // namespace boost
+
+#endif // BOOST_INTEROPERABLE_23022003THW_HPP