libstdc++-v3/testsuite/tr1/3_function_objects/function/4.cc

   1 // 2005-01-15 Douglas Gregor <dgregor@cs.indiana.edu>
   2 //
   3 // Copyright (C) 2005-2022 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10 //
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 3.7.2 polymorphic function object wrapper
  21 #include <tr1/functional>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_tr1.h>
  24
  25 using namespace __gnu_test;
  26
  27 // Put function objects into function<> wrappers
  28 void test04()
  29 {
  30   using std::tr1::function;
  31
  32   do_truncate_float_t truncate_float;
  33
  34   function<int(float)> f1(truncate_float);
  35   VERIFY( f1 );
  36   VERIFY( !!f1 );
  37   VERIFY( !(f1 == 0) );
  38   VERIFY( !(0 == f1) );
  39   VERIFY( f1 != 0 );
  40   VERIFY( 0 != f1 );
  41
  42   // Copy-construction
  43   function<int(float)> f2(f1);
  44   VERIFY( f2 );
  45
  46   // Invocation
  47   VERIFY( f1(3.1f) == 3 );
  48   VERIFY( f2(3.1f) == 3 );
  49
  50   // Assignment to zero
  51   f1 = 0;
  52   VERIFY( !f1 );
  53
  54   // Swap
  55   f1.swap(f2);
  56   VERIFY( f1 );
  57   VERIFY( !f2 );
  58   VERIFY( f1(3.1f) == 3 );
  59
  60   // Assignment from a function pointer
  61   f2 = do_truncate_float_t();
  62   VERIFY( f2(3.1f) == 3 );
  63
  64   // target_type and target() functions
  65   const function<int(float)>& f1c = f1;
  66   VERIFY( typeid(do_truncate_float_t) == f1.target_type() );
  67   VERIFY( f2.target<do_truncate_float_t>() != 0 );
  68   VERIFY( f1c.target<do_truncate_float_t>() != 0 );
  69 }
  70
  71 int main()
  72 {
  73   test04();
  74
  75   VERIFY( do_truncate_double_t::live_objects == 0 );
  76   VERIFY( do_truncate_float_t::live_objects == 0 );
  77
  78   return 0;
  79 }