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
10
11// <functional>
12
13// template<CopyConstructible Fn, CopyConstructible... Types>
14// unspecified bind(Fn, Types...); // constexpr since C++20
15// template<Returnable R, CopyConstructible Fn, CopyConstructible... Types>
16// unspecified bind(Fn, Types...); // constexpr since C++20
17
18// https://llvm.org/PR16343
19
20#include <functional>
21#include <cassert>
22
23#include "test_macros.h"
24
25struct multiply {
26 template <typename T>
27 TEST_CONSTEXPR_CXX20 T operator()(T a, T b) {
28 return a * b;
29 }
30};
31
32struct plus_one {
33 template <typename T>
34 TEST_CONSTEXPR_CXX20 T operator()(T a) {
35 return a + 1;
36 }
37};
38
39TEST_CONSTEXPR_CXX20 bool test() {
40 using std::placeholders::_1;
41 auto g = std::bind(f: multiply(), args: 2, args: _1);
42 assert(g(5) == 10);
43 assert(std::bind(plus_one(), g)(5) == 11);
44
45 return true;
46}
47
48int main(int, char**) {
49 test();
50#if TEST_STD_VER >= 20
51 static_assert(test());
52#endif
53
54 return 0;
55}
56

source code of libcxx/test/std/utilities/function.objects/bind/func.bind/func.bind.bind/nested.pass.cpp