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307d3d0ec8
- Split type class instances into separate files - Instances provided automatically by a type class are actually MCDs - Test each instance in a single file, not one file per method - Refactor the operator system to fix the ADL-related bug.
50 lines
1.2 KiB
C++
50 lines
1.2 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/detail/assert.hpp>
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#include <boost/hana/integral.hpp>
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#include <boost/hana/maybe.hpp>
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#include <boost/hana/tuple.hpp>
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using namespace boost::hana;
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int main() {
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//! [tuple]
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BOOST_HANA_CONSTEXPR_LAMBDA auto half = [](auto x) {
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return if_(x % int_<2> == int_<0>,
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just(x / int_<2>),
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nothing
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);
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};
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BOOST_HANA_CONSTANT_ASSERT(
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traverse<Maybe>(half, tuple(int_<2>, int_<4>, int_<6>))
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==
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just(tuple(int_<1>, int_<2>, int_<3>))
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);
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BOOST_HANA_CONSTANT_ASSERT(
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traverse<Maybe>(half, tuple(int_<2>, int_<3>, int_<6>))
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==
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nothing
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);
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//! [tuple]
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//! [maybe]
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BOOST_HANA_CONSTEXPR_LAMBDA auto twice = [](auto x) {
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return tuple(x, x);
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};
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BOOST_HANA_CONSTEXPR_ASSERT(
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traverse<Tuple>(twice, just('x')) == tuple(just('x'), just('x'))
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);
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BOOST_HANA_CONSTANT_ASSERT(
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traverse<Tuple>(twice, nothing) == tuple(nothing)
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);
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//! [maybe]
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}
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