| 1 | // Copyright Louis Dionne 2013-2022 |
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| 2 | // Distributed under the Boost Software License, Version 1.0. |
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| 3 | // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) |
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| 4 | |
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| 5 | #include <boost/hana/assert.hpp> |
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| 6 | #include <boost/hana/equal.hpp> |
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| 7 | #include <boost/hana/equal.hpp> |
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| 8 | #include <boost/hana/ext/std/integral_constant.hpp> |
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| 9 | #include <boost/hana/find_if.hpp> |
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| 10 | #include <boost/hana/functional/compose.hpp> |
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| 11 | #include <boost/hana/optional.hpp> |
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| 12 | #include <boost/hana/tuple.hpp> |
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| 13 | #include <boost/hana/type.hpp> |
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| 14 | |
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| 15 | #include <type_traits> |
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| 16 | namespace hana = boost::hana; |
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| 17 | |
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| 18 | |
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| 19 | // First get the type of the object, and then call the trait on it. |
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| 20 | constexpr auto is_integral = hana::compose(hana::trait<std::is_integral>, hana::typeid_); |
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| 21 | constexpr auto is_class = hana::compose(hana::trait<std::is_class>, hana::typeid_); |
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| 22 | |
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| 23 | static_assert( |
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| 24 | hana::find_if(hana::make_tuple(1.0, 2, '3'), is_integral) == hana::just(2) |
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| 25 | , "" ); |
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| 26 | |
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| 27 | BOOST_HANA_CONSTANT_CHECK( |
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| 28 | hana::find_if(hana::make_tuple(1.0, 2, '3'), is_class) == hana::nothing |
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| 29 | ); |
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| 30 | |
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| 31 | constexpr auto types = hana::tuple_t<char, int, unsigned, long, unsigned long>; |
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| 32 | BOOST_HANA_CONSTANT_CHECK( |
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| 33 | hana::find_if(types, hana::equal.to(hana::type_c<unsigned>)) == hana::just(hana::type_c<unsigned>) |
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| 34 | ); |
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| 35 | BOOST_HANA_CONSTANT_CHECK( |
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| 36 | hana::find_if(types, hana::equal.to(hana::type_c<void>)) == hana::nothing |
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| 37 | ); |
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| 38 | |
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| 39 | int main() { } |
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| 40 | |
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