llvm-project/libcxx/test/utilities/function.objects/func.memfn/member_function_const.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <functional>

// template<Returnable R, class T, CopyConstructible... Args>
//   unspecified mem_fn(R (T::* pm)(Args...) const);

#include <functional>
#include <cassert>

struct A
{
    char test0() const {return 'a';}
    char test1(int) const {return 'b';}
    char test2(int, double) const {return 'c';}
};

template <class F>
void
test0(F f)
{
    {
    A a;
    assert(f(a) == 'a');
    A* ap = &a;
    assert(f(ap) == 'a');
    const A* cap = &a;
    assert(f(cap) == 'a');
    }
}

template <class F>
void
test1(F f)
{
    {
    A a;
    assert(f(a, 1) == 'b');
    A* ap = &a;
    assert(f(ap, 2) == 'b');
    const A* cap = &a;
    assert(f(cap, 2) == 'b');
    }
}

template <class F>
void
test2(F f)
{
    {
    A a;
    assert(f(a, 1, 2) == 'c');
    A* ap = &a;
    assert(f(ap, 2, 3.5) == 'c');
    const A* cap = &a;
    assert(f(cap, 2, 3.5) == 'c');
    }
}

int main()
{
    test0(std::mem_fn(&A::test0));
    test1(std::mem_fn(&A::test1));
    test2(std::mem_fn(&A::test2));
}