27 lines
669 B
C++
27 lines
669 B
C++
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// Copyright (C) 2009-2012 Lorenzo Caminiti
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// Distributed under the Boost Software License, Version 1.0
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// (see accompanying file LICENSE_1_0.txt or a copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// Home at http://www.boost.org/libs/local_function
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#ifndef ADDABLE_HPP_
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#define ADDABLE_HPP_
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#include <boost/concept_check.hpp>
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template<typename T>
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struct Addable { // User-defined concept.
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BOOST_CONCEPT_USAGE(Addable) {
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return_type(x + y); // Check addition `T operator+(T x, T y)`.
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}
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private:
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void return_type(T) {} // Implementation (required for some linkers).
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static T const& x;
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static T const& y;
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};
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#endif // #include guard
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