1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14
10
11// <set>
12
13// template<class InputIterator,
14// class Compare = less<iter-value-type<InputIterator>>,
15// class Allocator = allocator<iter-value-type<InputIterator>>>
16// set(InputIterator, InputIterator,
17// Compare = Compare(), Allocator = Allocator())
18// -> set<iter-value-type<InputIterator>, Compare, Allocator>;
19// template<class Key, class Compare = less<Key>,
20// class Allocator = allocator<Key>>
21// set(initializer_list<Key>, Compare = Compare(), Allocator = Allocator())
22// -> set<Key, Compare, Allocator>;
23// template<class InputIterator, class Allocator>
24// set(InputIterator, InputIterator, Allocator)
25// -> set<iter-value-type<InputIterator>,
26// less<iter-value-type<InputIterator>>, Allocator>;
27// template<class Key, class Allocator>
28// set(initializer_list<Key>, Allocator)
29// -> set<Key, less<Key>, Allocator>;
30
31#include <functional>
32#include <set>
33#include <type_traits>
34
35struct NotAnAllocator {
36 friend bool operator<(NotAnAllocator, NotAnAllocator) { return false; }
37};
38
39int main(int, char**) {
40 {
41 // cannot deduce Key from nothing
42 std::set s;
43 // expected-error-re@-1{{no viable constructor or deduction guide for deduction of template arguments of '{{(std::)?}}set'}}
44 }
45 {
46 // cannot deduce Key from just (Compare)
47 std::set s(std::less<int>{});
48 // expected-error-re@-1{{no viable constructor or deduction guide for deduction of template arguments of '{{(std::)?}}set'}}
49 }
50 {
51 // cannot deduce Key from just (Compare, Allocator)
52 std::set s(std::less<int>{}, std::allocator<int>{});
53 // expected-error-re@-1{{no viable constructor or deduction guide for deduction of template arguments of '{{(std::)?}}set'}}
54 }
55 {
56 // cannot deduce Key from just (Allocator)
57 std::set s(std::allocator<int>{});
58 // expected-error-re@-1{{no viable constructor or deduction guide for deduction of template arguments of '{{(std::)?}}set'}}
59 }
60 {
61 // since we have parens, not braces, this deliberately does not find the
62 // initializer_list constructor
63 NotAnAllocator a;
64 std::set s(a);
65 // expected-error-re@-1{{no viable constructor or deduction guide for deduction of template arguments of '{{(std::)?}}set'}}
66 }
67
68 return 0;
69}
70

source code of libcxx/test/std/containers/associative/set/set.cons/deduct.verify.cpp