libcxx/test/utilities/utility/pairs/pair.piecewise/piecewise_construct.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.
//
//===----------------------------------------------------------------------===//

// <utility>

// template <class T1, class T2> struct pair

// struct piecewise_construct_t { };
// constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();

#include <utility>
#include <tuple>
#include <cassert>

class A
{
    int i_;
    char c_;
public:
    A(int i, char c) : i_(i), c_(c) {}
    int get_i() const {return i_;}
    char get_c() const {return c_;}
};

class B
{
    double d_;
    unsigned u1_;
    unsigned u2_;
public:
    B(double d, unsigned u1, unsigned u2) : d_(d), u1_(u1), u2_(u2) {}
    double get_d() const {return d_;}
    unsigned get_u1() const {return u1_;}
    unsigned get_u2() const {return u2_;}
};

int main()
{
#ifndef _LIBCPP_HAS_NO_VARIADICS
    std::pair<A, B> p(std::piecewise_construct,
                      std::make_tuple(4, 'a'),
                      std::make_tuple(3.5, 6u, 2u));
    assert(p.first.get_i() == 4);
    assert(p.first.get_c() == 'a');
    assert(p.second.get_d() == 3.5);
    assert(p.second.get_u1() == 6u);
    assert(p.second.get_u2() == 2u);
#endif
}