hana/test/issues/github_365.cpp
Louis Dionne a525aab0f4 Add tests to make sure that hana::accessors does not decay arrays to pointers
Also, add tests to validate that `hana::tuple` containing an array can't be
constructed from an array, per the standard. Related to #365.
2018-01-01 14:38:18 -08:00

62 lines
1.7 KiB
C++

// 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/accessors.hpp>
#include <boost/hana/adapt_struct.hpp>
#include <boost/hana/assert.hpp>
#include <boost/hana/at.hpp>
#include <boost/hana/define_struct.hpp>
#include <boost/hana/second.hpp>
#include <cstddef>
#include <type_traits>
namespace hana = boost::hana;
//
// This test makes sure that `hana::accessors` does not decay C-style array
// members to pointers.
//
struct Foo {
float array[3];
};
BOOST_HANA_ADAPT_STRUCT(Foo,
array
);
template <std::size_t N>
using FloatArray = float[N];
struct Bar {
BOOST_HANA_DEFINE_STRUCT(Bar,
(FloatArray<3>, array)
);
};
int main() {
{
Foo foo = {{1.0f, 2.0f, 3.0f}};
auto accessors = hana::accessors<Foo>();
auto get_array = hana::second(hana::at_c<0>(accessors));
static_assert(std::is_same<decltype(get_array(foo)), float(&)[3]>{}, "");
float (&array)[3] = get_array(foo);
BOOST_HANA_RUNTIME_CHECK(array[0] == 1.0f);
BOOST_HANA_RUNTIME_CHECK(array[1] == 2.0f);
BOOST_HANA_RUNTIME_CHECK(array[2] == 3.0f);
}
{
Bar bar = {{1.0f, 2.0f, 3.0f}};
auto accessors = hana::accessors<Bar>();
auto get_array = hana::second(hana::at_c<0>(accessors));
static_assert(std::is_same<decltype(get_array(bar)), float(&)[3]>{}, "");
float (&array)[3] = get_array(bar);
BOOST_HANA_RUNTIME_CHECK(array[0] == 1.0f);
BOOST_HANA_RUNTIME_CHECK(array[1] == 2.0f);
BOOST_HANA_RUNTIME_CHECK(array[2] == 3.0f);
}
}