1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// XFAIL: dylib-has-no-bad_variant_access && !libcpp-no-exceptions
// <variant>
// template <class ...Types> class variant;
// template <class T, class U, class ...Args>
// T& emplace(initializer_list<U> il,Args&&... args);
#include <cassert>
#include <string>
#include <type_traits>
#include <variant>
#include "archetypes.hpp"
#include "test_convertible.hpp"
#include "test_macros.h"
struct InitList {
std::size_t size;
constexpr InitList(std::initializer_list<int> il) : size(il.size()) {}
};
struct InitListArg {
std::size_t size;
int value;
constexpr InitListArg(std::initializer_list<int> il, int v)
: size(il.size()), value(v) {}
};
template <class Var, class T, class... Args>
constexpr auto test_emplace_exists_imp(int) -> decltype(
std::declval<Var>().template emplace<T>(std::declval<Args>()...), true) {
return true;
}
template <class, class, class...>
constexpr auto test_emplace_exists_imp(long) -> bool {
return false;
}
template <class... Args> constexpr bool emplace_exists() {
return test_emplace_exists_imp<Args...>(0);
}
void test_emplace_sfinae() {
using V =
std::variant<int, TestTypes::NoCtors, InitList, InitListArg, long, long>;
using IL = std::initializer_list<int>;
static_assert(emplace_exists<V, InitList, IL>(), "");
static_assert(!emplace_exists<V, InitList, int>(), "args don't match");
static_assert(!emplace_exists<V, InitList, IL, int>(), "too many args");
static_assert(emplace_exists<V, InitListArg, IL, int>(), "");
static_assert(!emplace_exists<V, InitListArg, int>(), "args don't match");
static_assert(!emplace_exists<V, InitListArg, IL>(), "too few args");
static_assert(!emplace_exists<V, InitListArg, IL, int, int>(),
"too many args");
}
void test_basic() {
using V = std::variant<int, InitList, InitListArg, TestTypes::NoCtors>;
V v;
auto& ref1 = v.emplace<InitList>({1, 2, 3});
static_assert(std::is_same_v<InitList&,decltype(ref1)>, "");
assert(std::get<InitList>(v).size == 3);
assert(&ref1 == &std::get<InitList>(v));
auto& ref2 = v.emplace<InitListArg>({1, 2, 3, 4}, 42);
static_assert(std::is_same_v<InitListArg&,decltype(ref2)>, "");
assert(std::get<InitListArg>(v).size == 4);
assert(std::get<InitListArg>(v).value == 42);
assert(&ref2 == &std::get<InitListArg>(v));
auto& ref3 = v.emplace<InitList>({1});
static_assert(std::is_same_v<InitList&,decltype(ref3)>, "");
assert(std::get<InitList>(v).size == 1);
assert(&ref3 == &std::get<InitList>(v));
}
int main(int, char**) {
test_basic();
test_emplace_sfinae();
return 0;
}
|
