| 1 | /* |
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| 2 | Copyright 2017 Glen Joseph Fernandes |
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| 3 | (glenjofe@gmail.com) |
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| 4 | |
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| 5 | Distributed under the Boost Software License, |
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| 6 | Version 1.0. (See accompanying file LICENSE_1_0.txt |
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| 7 | or copy at http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | */ |
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| 9 | |
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| 10 | #ifndef BOOST_TT_MAKE_VOID_HPP_INCLUDED |
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| 11 | #define BOOST_TT_MAKE_VOID_HPP_INCLUDED |
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| 12 | |
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| 13 | #include <boost/config.hpp> |
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| 14 | |
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| 15 | namespace boost { |
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| 16 | |
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| 17 | #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
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| 18 | template<class...> |
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| 19 | struct make_void { |
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| 20 | typedef void type; |
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| 21 | }; |
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| 22 | |
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| 23 | #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) |
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| 24 | template<class... Ts> |
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| 25 | using void_t = typename make_void<Ts...>::type; |
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| 26 | #endif |
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| 27 | |
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| 28 | #else /* BOOST_NO_CXX11_VARIADIC_TEMPLATES */ |
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| 29 | |
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| 30 | template<class = void, |
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| 31 | class = void, |
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| 32 | class = void, |
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| 33 | class = void, |
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| 34 | class = void> |
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| 35 | struct make_void { |
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| 36 | typedef void type; |
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| 37 | }; |
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| 38 | |
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| 39 | #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) |
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| 40 | template<class A = void, |
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| 41 | class B = void, |
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| 42 | class C = void, |
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| 43 | class D = void, |
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| 44 | class E = void> |
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| 45 | using void_t = typename make_void<A, B, C, D, E>::type; |
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| 46 | #endif |
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| 47 | |
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| 48 | #endif |
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| 49 | |
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| 50 | } /* boost */ |
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| 51 | |
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| 52 | #endif |
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| 53 | |
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