libstdc++-v3/testsuite/25_algorithms/for_each/constrained.cc

   1 // Copyright (C) 2020-2023 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-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <algorithm>
  22 #include <functional>
  23 #include <testsuite_hooks.h>
  24 #include <testsuite_iterators.h>
  25
  26 using __gnu_test::test_container;
  27 using __gnu_test::test_range;
  28 using __gnu_test::input_iterator_wrapper;
  29 using __gnu_test::forward_iterator_wrapper;
  30 using __gnu_test::random_access_iterator_wrapper;
  31
  32 namespace ranges = std::ranges;
  33
  34 struct X { int i; };
  35
  36 static int a;
  37
  38 void
  39 f(int& i)
  40 {
  41   a += i;
  42 }
  43
  44 void
  45 test01()
  46 {
  47   X x[] = { {2}, {4}, {6}, {8}, {10}, {11} };
  48
  49   auto res = ranges::for_each(x, x+6, f, &X::i);
  50   VERIFY( res.in == x+6 );
  51   VERIFY( res.fun == &f );
  52   VERIFY( a == 41 );
  53
  54   test_container<X, forward_iterator_wrapper> c(x);
  55   int p = 0;
  56   ranges::for_each(c, [&p](int i) { ++p; }, &X::i);
  57   VERIFY( p == 6 );
  58
  59   test_range<X, input_iterator_wrapper> r(x);
  60   int q = 0;
  61   ranges::for_each(r, [&q](X&) { ++q; });
  62   VERIFY( q == 6 );
  63 }
  64
  65 struct Y { int i; int j; };
  66
  67 void
  68 test02()
  69 {
  70   auto f = []
  71   {
  72     Y y[] = { {1,2}, {2,4}, {3,6} };
  73     int a = 0;
  74     ranges::for_each(y, [&a](int i) { a += i; }, &Y::i);
  75     return a;
  76   };
  77   static_assert(f() == 6);
  78 }
  79
  80 template<template<typename> typename wrapper>
  81 void
  82 test03()
  83 {
  84   int x[] = {1,2,3,4,5};
  85   test_range<int, wrapper> rx(x);
  86   int s = 0;
  87   auto func = [&s](int i){ s += i; };
  88   auto [i,f] = ranges::for_each_n(rx.begin(), 3, func);
  89   VERIFY( i.ptr = x+3 );
  90   VERIFY( s == 1+2+3 );
  91   f(1);
  92   VERIFY( s == 1+2+3+1 );
  93
  94   s = 0;
  95   rx.bounds.first = x;
  96   auto [j,g] = ranges::for_each_n(rx.begin(), -1, func);
  97   VERIFY( j.ptr == x );
  98   VERIFY( s == 0 );
  99   g(1);
 100   VERIFY( s == 1 );
 101
 102   s = 0;
 103   rx.bounds.first = x;
 104   auto [k,h] = ranges::for_each_n(rx.begin(), 5, func, std::negate<>{});
 105   VERIFY( k.ptr == x+5 );
 106   VERIFY( s == -(1+2+3+4+5) );
 107   h(-6);
 108   VERIFY( s == -(1+2+3+4+5+6) );
 109 }
 110
 111 constexpr bool
 112 test04()
 113 {
 114   int x[] = {1,2,3,4,5};
 115   int p = 1;
 116   ranges::for_each_n(x+1, 4, [&p](int i){ p*=i; }, [](int i){ return i+1; });
 117   return p == 3*4*5*6;
 118 }
 119
 120 int
 121 main()
 122 {
 123   test01();
 124   test02();
 125   test03<input_iterator_wrapper>();
 126   test03<random_access_iterator_wrapper>();
 127   static_assert(test04());
 128 }