sources/cxx-stl/llvm-libc++/test/std/containers/sequences/list/list.modifiers/emplace_back.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++98, c++03

// <list>

// template <class... Args> reference emplace_back(Args&&... args);
// return type is 'reference' in C++17; 'void' before

#include <list>
#include <cassert>

#include "test_macros.h"
#include "min_allocator.h"

class A
{
    int i_;
    double d_;

    A(const A&);
    A& operator=(const A&);
public:
    A(int i, double d)
        : i_(i), d_(d) {}

    int geti() const {return i_;}
    double getd() const {return d_;}
};

int main()
{
    {
    std::list<A> c;
#if TEST_STD_VER > 14
    A& r1 = c.emplace_back(2, 3.5);
    assert(c.size() == 1);
    assert(&r1 == &c.back());
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    A& r2 = c.emplace_back(3, 4.5);
    assert(c.size() == 2);
    assert(&r2 == &c.back());
#else
    c.emplace_back(2, 3.5);
    assert(c.size() == 1);
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    c.emplace_back(3, 4.5);
    assert(c.size() == 2);
#endif
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    assert(c.back().geti() == 3);
    assert(c.back().getd() == 4.5);
    }
    {
    std::list<A, min_allocator<A>> c;
#if TEST_STD_VER > 14
    A& r1 = c.emplace_back(2, 3.5);
    assert(c.size() == 1);
    assert(&r1 == &c.back());
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    A& r2 = c.emplace_back(3, 4.5);
    assert(c.size() == 2);
    assert(&r2 == &c.back());
#else
    c.emplace_back(2, 3.5);
    assert(c.size() == 1);
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    c.emplace_back(3, 4.5);
    assert(c.size() == 2);
#endif
    assert(c.front().geti() == 2);
    assert(c.front().getd() == 3.5);
    assert(c.back().geti() == 3);
    assert(c.back().getd() == 4.5);
    }
}