| 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/fwd/concept/integral_constant.hpp> |
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| 7 | #include <boost/hana/repeat.hpp> |
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| 8 | namespace hana = boost::hana; |
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| 9 | |
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| 10 | |
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| 11 | ////////////////////////////////////////////////////////////////////////////// |
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| 12 | // Define a simple model of IntegralConstant for use below |
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| 13 | template <int i> |
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| 14 | struct constant { |
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| 15 | static constexpr int value = i; |
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| 16 | using value_type = int; |
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| 17 | }; |
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| 18 | |
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| 19 | namespace boost { namespace hana { |
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| 20 | template <int i> |
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| 21 | struct IntegralConstant<constant<i>> { |
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| 22 | static constexpr bool value = true; |
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| 23 | }; |
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| 24 | |
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| 25 | // definition of `to<>` omitted |
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| 26 | }} |
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| 27 | ////////////////////////////////////////////////////////////////////////////// |
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| 28 | |
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| 29 | void function() { } |
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| 30 | |
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| 31 | int main() { |
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| 32 | int counter = 0; |
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| 33 | hana::repeat(constant<3>{}, [&] { ++counter; }); |
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| 34 | BOOST_HANA_RUNTIME_CHECK(counter == 3); |
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| 35 | |
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| 36 | // Try with a normal function. |
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| 37 | hana::repeat(constant<3>{}, function); |
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| 38 | |
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| 39 | // Try with a function pointer. |
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| 40 | hana::repeat(constant<3>{}, static_cast<void(*)()>(function)); |
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| 41 | |
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| 42 | // Make sure we don't read from a non-constexpr variable. |
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| 43 | constant<3> three{}; |
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| 44 | hana::repeat(three, []{}); |
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| 45 | } |
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| 46 | |
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