libstdc++-v3/testsuite/20_util/function/3.cc

   1 // { dg-do run { target c++11 } }
   2 // 2005-01-15 Douglas Gregor <dgregor@cs.indiana.edu>
   3 //
   4 // Copyright (C) 2005-2020 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 // 20.7.15 polymorphic function object wrapper
  22 #include <functional>
  23 #include <testsuite_hooks.h>
  24 #include <testsuite_tr1.h>
  25
  26 using namespace __gnu_test;
  27
  28 // Put nearly-matching function pointers into function<> wrappers
  29 void test03()
  30 {
  31   using std::function;
  32
  33   function<int(float)> f1(truncate_double);
  34   VERIFY( f1 );
  35   VERIFY( !!f1 );
  36   VERIFY( !(f1 == 0) );
  37   VERIFY( !(0 == f1) );
  38   VERIFY( f1 != 0 );
  39   VERIFY( 0 != f1 );
  40
  41   // Copy-construction
  42   function<int(float)> f2(f1);
  43   VERIFY( f2 );
  44
  45   // Invocation
  46   VERIFY( f1(3.1f) == 3 );
  47   VERIFY( f2(3.1f) == 3 );
  48
  49   // Assignment to zero
  50   f1 = 0;
  51   VERIFY( !f1 );
  52
  53   // Swap
  54   f1.swap(f2);
  55   VERIFY( f1 );
  56   VERIFY( !f2 );
  57   VERIFY( f1(3.1f) == 3 );
  58
  59   // Assignment from a function pointer
  60   f2 = truncate_double;
  61   VERIFY( f2(3.1f) == 3 );
  62
  63   // target_type and target() functions
  64   const function<int(float)>& f1c = f1;
  65   VERIFY( typeid(long(*)(double)) == f1.target_type() );
  66   VERIFY( f2.target<long(*)(double)>() != 0 );
  67   VERIFY( *f2.target<long(*)(double)>() == &truncate_double );
  68   VERIFY( f1c.target<long(*)(double)>() != 0 );
  69   VERIFY( *f1c.target<long(*)(double)>() == &truncate_double );
  70 }
  71
  72 int main()
  73 {
  74   test03();
  75   return 0;
  76 }