libstdc++-v3/testsuite/20_util/function_objects/invoke/ref_ext.cc

   1 // Copyright (C) 2015-2021 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do compile { target c++11 } }
  19
  20 #include <functional>
  21
  22 struct A {
  23   void foo(int) { }
  24 };
  25
  26 void
  27 test01()
  28 {
  29   // PR libstdc++/59768
  30   A a;
  31   auto ref = std::ref(a);
  32   std::__invoke(&A::foo, ref, 100);             // lvalue
  33   std::__invoke(&A::foo, std::move(ref), 100);  // rvalue
  34   const auto refc = std::ref(a);
  35   std::__invoke(&A::foo, refc, 100);            // const lvalue
  36   std::__invoke(&A::foo, std::move(refc), 100); // const rvalue
  37 }
  38
  39 struct B {
  40   int bar = 0;
  41 };
  42
  43 void
  44 test02()
  45 {
  46   B b;
  47   // Invocation through a reference_wrapper means the object is an lvalue.
  48
  49   int* ptr [[gnu::unused]];
  50   auto ref = std::ref(b);
  51   ptr = &std::__invoke(&B::bar, ref);
  52   ptr = &std::__invoke(&B::bar, std::move(ref));
  53
  54   const int* cptr [[gnu::unused]];
  55   auto cref = std::cref(b);
  56   cptr = &std::__invoke(&B::bar, cref);
  57   cptr = &std::__invoke(&B::bar, std::move(cref));
  58 }