58 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++1110 11// <functional>12 13// template<class T> struct is_bind_expression;14// A program may specialize this template for a program-defined type T15// to have a base characteristic of true_type to indicate that T should16// be treated as a subexpression in a bind call.17// https://llvm.org/PR5175318 19#include <cassert>20#include <functional>21#include <type_traits>22#include <utility>23 24struct MyBind {25 int operator()(int x, int y) const { return 10*x + y; }26};27template<> struct std::is_bind_expression<MyBind> : std::true_type {};28 29int 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