39 lines
1.2 KiB
C++
39 lines
1.2 KiB
C++
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//
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// Copyright (c) 2020 Alexander Grund
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//
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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#ifndef BOOST_NOWIDE_DETAIL_IS_PATH_HPP_INCLUDED
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#define BOOST_NOWIDE_DETAIL_IS_PATH_HPP_INCLUDED
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#include <type_traits>
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namespace boost {
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namespace nowide {
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namespace detail {
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/// Trait to heuristically check for a *\::filesystem::path
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/// Done by checking for make_preferred and filename member functions with correct signature
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template<typename T>
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struct is_path
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{
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template<typename U, U& (U::*)(), U (U::*)() const>
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struct Check;
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template<typename U>
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static std::true_type test(Check<U, &U::make_preferred, &U::filename>*);
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template<typename U>
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static std::false_type test(...);
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static constexpr bool value = decltype(test<T>(0))::value;
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};
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/// SFINAE trait which has a member "type = Result" if the Path is a *\::filesystem::path
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template<typename Path, typename Result>
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using enable_if_path_t = typename std::enable_if<is_path<Path>::value, Result>::type;
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} // namespace detail
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} // namespace nowide
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} // namespace boost
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#endif
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