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This is because using variable templates limits the objects to being constexpr, or to not being constexpr (but then initializing the object becomes an issue). This is also a step towards being compilable by GCC 4.9, but that only would not justify the change.
44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
/*
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@copyright Louis Dionne 2014
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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*/
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#include <boost/hana/assert.hpp>
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#include <boost/hana/ext/std/integral_constant.hpp>
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#include <boost/hana/integral.hpp>
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using namespace boost::hana;
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int main() {
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{
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//! [integral_constant]
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BOOST_HANA_CONSTANT_CHECK(
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integral_constant<Integral<int>, 2>()
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==
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int_<2>
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);
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BOOST_HANA_CONSTANT_CHECK(equal(
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integral_constant<ext::std::IntegralConstant<bool>, true>(),
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std::true_type{}
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));
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//! [integral_constant]
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}
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{
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//! [enumerable]
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BOOST_HANA_CONSTANT_CHECK(
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succ(integral_constant<Integral<int>, 2>())
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==
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integral_constant<Integral<int>, 3>()
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);
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BOOST_HANA_CONSTANT_CHECK(
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pred(integral_constant<Integral<int>, 2>())
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==
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integral_constant<Integral<int>, 1>()
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);
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//! [enumerable]
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}
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}
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