llvm-project/libcxx/test/std/utilities/utility/utility.inplace/inplace.pass.cpp

99 lines
3.2 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <utility>
// struct in_place_tag { in_place_tag() = delete; };
//
// using in_place_t = in_place_tag(&)(unspecified);
// template <class T>
// using in_place_type_t = in_place_tag(&)(unspecified<T>);
// template <size_t N>
// using in_place_index_t = in_place_tag(&)(unspecified<N>);
//
// in_place_tag in_place(unspecified);
//
// template <class T>;
// in_place_tag in_place(unspecified<T>);
//
// template <size_t N>
// in_place_tag in_place(unspecified<N>);
#include <utility>
#include <cassert>
#include <memory>
#include "test_macros.h"
#include "type_id.h"
template <class Tp>
struct CheckRet : std::false_type {};
template <class Arg>
struct CheckRet<std::in_place_tag(Arg)> : std::true_type {};
TypeID const* test_fn(std::in_place_t) { return &makeTypeID<std::in_place_t>(); }
template <class T>
TypeID const* test_fn(std::in_place_type_t<T>)
{ return &makeTypeID<std::in_place_type_t<T>>(); }
template <size_t I>
TypeID const* test_fn(std::in_place_index_t<I>)
{ return &makeTypeID<std::in_place_index_t<I>>(); }
// Concrete test overloads that don't have to be deduced.
template <class Tag>
TypeID const* concrete_test_fn(Tag) { return &makeTypeID<Tag>(); }
template <class Tp>
bool check_tag_basic() {
using RawTp = typename std::remove_reference<Tp>::type;
static_assert(std::is_lvalue_reference<Tp>::value, "");
static_assert(std::is_function<RawTp>::value, "");
static_assert(CheckRet<RawTp>::value, "");
auto concrete_fn = concrete_test_fn<Tp>;
return test_fn((Tp)std::in_place) == &makeTypeID<Tp>()
&& concrete_fn(std::in_place) == &makeTypeID<Tp>();
}
int main() {
// test in_place_tag
{
static_assert(!std::is_default_constructible<std::in_place_tag>::value, "");
}
// test in_place_t
{
using T = std::in_place_t;
assert(check_tag_basic<std::in_place_t>());
assert(test_fn((T)std::in_place) == &makeTypeID<T>());
}
// test in_place_type_t
{
using T1 = std::in_place_type_t<void>;
using T2 = std::in_place_type_t<int>;
using T3 = std::in_place_type_t<const int>;
assert(check_tag_basic<T1>());
assert(check_tag_basic<T2>());
assert(check_tag_basic<T3>());
static_assert(!std::is_same<T1, T2>::value && !std::is_same<T1, T3>::value, "");
static_assert(!std::is_same<T2, T3>::value, "");
}
// test in_place_index_t
{
using T1 = std::in_place_index_t<0>;
using T2 = std::in_place_index_t<1>;
using T3 = std::in_place_index_t<static_cast<size_t>(-1)>;
assert(check_tag_basic<T1>());
assert(check_tag_basic<T2>());
assert(check_tag_basic<T3>());
static_assert(!std::is_same<T1, T2>::value && !std::is_same<T1, T3>::value, "");
static_assert(!std::is_same<T2, T3>::value, "");
}
}