diff options
Diffstat (limited to 'src/boost/libs/hana/test/type/metafunction_class.cpp')
-rw-r--r-- | src/boost/libs/hana/test/type/metafunction_class.cpp | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/src/boost/libs/hana/test/type/metafunction_class.cpp b/src/boost/libs/hana/test/type/metafunction_class.cpp new file mode 100644 index 000000000..b0123708b --- /dev/null +++ b/src/boost/libs/hana/test/type/metafunction_class.cpp @@ -0,0 +1,73 @@ +// Copyright Louis Dionne 2013-2017 +// Distributed under the Boost Software License, Version 1.0. +// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) + +#include <boost/hana/assert.hpp> +#include <boost/hana/concept/metafunction.hpp> +#include <boost/hana/equal.hpp> +#include <boost/hana/not.hpp> +#include <boost/hana/type.hpp> + +#include <type_traits> +namespace hana = boost::hana; + + +struct x1; struct x2; struct x3; +struct y1 { }; struct y2 { }; struct y3 { }; +struct f { template <typename ...> struct apply { struct type; }; }; + +template <typename F, typename ...T> +constexpr auto valid_call(F f, T ...t) -> decltype(((void)f(t...)), true) +{ return true; } +constexpr auto valid_call(...) +{ return false; } + +BOOST_HANA_CONSTANT_CHECK(hana::equal( + hana::metafunction_class<f>(), + hana::type_c<f::apply<>::type> +)); +BOOST_HANA_CONSTANT_CHECK(hana::equal( + hana::metafunction_class<f>(hana::type_c<x1>), + hana::type_c<f::apply<x1>::type> +)); +BOOST_HANA_CONSTANT_CHECK(hana::equal( + hana::metafunction_class<f>(hana::type_c<x1>, hana::type_c<x2>), + hana::type_c<f::apply<x1, x2>::type> +)); +BOOST_HANA_CONSTANT_CHECK(hana::equal( + hana::metafunction_class<f>(hana::type_c<x1>, hana::type_c<x2>, hana::type_c<x3>), + hana::type_c<f::apply<x1, x2, x3>::type> +)); + +using F = decltype(hana::metafunction_class<f>); +static_assert(std::is_same<F::apply<>, f::apply<>>{}, ""); +static_assert(std::is_same<F::apply<x1>, f::apply<x1>>{}, ""); +static_assert(std::is_same<F::apply<x1, x2>, f::apply<x1, x2>>{}, ""); +static_assert(std::is_same<F::apply<x1, x2, x3>, f::apply<x1, x2, x3>>{}, ""); + +// Make sure we're SFINAE-friendly +struct no_type { template <typename ...> struct apply { }; }; +static_assert(!valid_call(hana::metafunction_class<no_type>), ""); +static_assert(!valid_call(hana::metafunction_class<no_type>, hana::type_c<x1>), ""); + +// Make sure we model the Metafunction concept +static_assert(hana::Metafunction<decltype(hana::metafunction_class<f>)>::value, ""); +static_assert(hana::Metafunction<decltype(hana::metafunction_class<f>)&>::value, ""); + +// Make sure metafunction_class is SFINAE-friendly +struct not_a_mfc1 { template <typename ...> struct apply { }; }; +struct not_a_mfc2 { }; +BOOST_HANA_CONSTANT_CHECK(hana::not_( + hana::is_valid(hana::metafunction_class<not_a_mfc1>)(hana::type_c<void>) +)); +BOOST_HANA_CONSTANT_CHECK(hana::not_( + hana::is_valid(hana::metafunction_class<not_a_mfc2>)(hana::type_c<void>) +)); + + +// Make sure we don't read from a non-constexpr variable +int main() { + auto t = hana::type_c<x1>; + constexpr auto r = hana::metafunction_class<f>(t); + (void)r; +} |