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
10
11 // <functional>
12
13 // template<class T> struct is_bind_expression;
14 // A program may specialize this template for a program-defined type T
15 // to have a base characteristic of true_type to indicate that T should
16 // be treated as a subexpression in a bind call.
17 // https://llvm.org/PR51753
18
19 #include <cassert>
20 #include <functional>
21 #include <type_traits>
22 #include <utility>
23
24 struct MyBind {
operator ()MyBind25 int operator()(int x, int y) const { return 10*x + y; }
26 };
27 template<> struct std::is_bind_expression<MyBind> : std::true_type {};
28
main(int,char **)29 int main(int, char**)
30 {
31 {
32 auto f = [](auto x) { return 10*x + 9; };
33 MyBind bindexpr;
34 auto bound = std::bind(f, bindexpr);
35 assert(bound(7, 8) == 789);
36 }
37 {
38 auto f = [](auto x) { return 10*x + 9; };
39 const MyBind bindexpr;
40 auto bound = std::bind(f, bindexpr);
41 assert(bound(7, 8) == 789);
42 }
43 {
44 auto f = [](auto x) { return 10*x + 9; };
45 MyBind bindexpr;
46 auto bound = std::bind(f, std::move(bindexpr));
47 assert(bound(7, 8) == 789);
48 }
49 {
50 auto f = [](auto x) { return 10*x + 9; };
51 const MyBind bindexpr;
52 auto bound = std::bind(f, std::move(bindexpr));
53 assert(bound(7, 8) == 789);
54 }
55
56 return 0;
57 }
58