libcxx/test/std/containers/sequences/list/list.modifiers/emplace_back.pass.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03
  10
  11 // <list>
  12
  13 // template <class... Args> reference emplace_back(Args&&... args);
  14 // return type is 'reference' in C++17; 'void' before
  15
  16 #include <list>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "min_allocator.h"
  21
  22 class A
  23 {
  24     int i_;
  25     double d_;
  26
  27     A(const A&);
  28     A& operator=(const A&);
  29 public:
  30     A(int i, double d)
  31         : i_(i), d_(d) {}
  32
  33     int geti() const {return i_;}
  34     double getd() const {return d_;}
  35 };
  36
  37 int main(int, char**)
  38 {
  39     {
  40     std::list<A> c;
  41 #if TEST_STD_VER > 14
  42     A& r1 = c.emplace_back(2, 3.5);
  43     assert(c.size() == 1);
  44     assert(&r1 == &c.back());
  45     assert(c.front().geti() == 2);
  46     assert(c.front().getd() == 3.5);
  47     A& r2 = c.emplace_back(3, 4.5);
  48     assert(c.size() == 2);
  49     assert(&r2 == &c.back());
  50 #else
  51     c.emplace_back(2, 3.5);
  52     assert(c.size() == 1);
  53     assert(c.front().geti() == 2);
  54     assert(c.front().getd() == 3.5);
  55     c.emplace_back(3, 4.5);
  56     assert(c.size() == 2);
  57 #endif
  58     assert(c.front().geti() == 2);
  59     assert(c.front().getd() == 3.5);
  60     assert(c.back().geti() == 3);
  61     assert(c.back().getd() == 4.5);
  62     }
  63     {
  64     std::list<A, min_allocator<A>> c;
  65 #if TEST_STD_VER > 14
  66     A& r1 = c.emplace_back(2, 3.5);
  67     assert(c.size() == 1);
  68     assert(&r1 == &c.back());
  69     assert(c.front().geti() == 2);
  70     assert(c.front().getd() == 3.5);
  71     A& r2 = c.emplace_back(3, 4.5);
  72     assert(c.size() == 2);
  73     assert(&r2 == &c.back());
  74 #else
  75     c.emplace_back(2, 3.5);
  76     assert(c.size() == 1);
  77     assert(c.front().geti() == 2);
  78     assert(c.front().getd() == 3.5);
  79     c.emplace_back(3, 4.5);
  80     assert(c.size() == 2);
  81 #endif
  82     assert(c.front().geti() == 2);
  83     assert(c.front().getd() == 3.5);
  84     assert(c.back().geti() == 3);
  85     assert(c.back().getd() == 4.5);
  86     }
  87
  88   return 0;
  89 }