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

   1 // Copyright (C) 2020-2025 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 run { target c++20 } }
  19
  20 #include <algorithm>
  21 #include <functional>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_iterators.h>
  24
  25 using __gnu_test::test_container;
  26 using __gnu_test::test_range;
  27 using __gnu_test::input_iterator_wrapper;
  28 using __gnu_test::forward_iterator_wrapper;
  29 using __gnu_test::random_access_iterator_wrapper;
  30
  31 namespace ranges = std::ranges;
  32
  33 struct X { int i; };
  34
  35 static int a;
  36
  37 void
  38 f(int& i)
  39 {
  40   a += i;
  41 }
  42
  43 void
  44 test01()
  45 {
  46   X x[] = { {2}, {4}, {6}, {8}, {10}, {11} };
  47
  48   auto res = ranges::for_each(x, x+6, f, &X::i);
  49   VERIFY( res.in == x+6 );
  50   VERIFY( res.fun == &f );
  51   VERIFY( a == 41 );
  52
  53   test_container<X, forward_iterator_wrapper> c(x);
  54   int p = 0;
  55   ranges::for_each(c, [&p](int i) { ++p; }, &X::i);
  56   VERIFY( p == 6 );
  57
  58   test_range<X, input_iterator_wrapper> r(x);
  59   int q = 0;
  60   ranges::for_each(r, [&q](X&) { ++q; });
  61   VERIFY( q == 6 );
  62 }
  63
  64 struct Y { int i; int j; };
  65
  66 void
  67 test02()
  68 {
  69   auto f = []
  70   {
  71     Y y[] = { {1,2}, {2,4}, {3,6} };
  72     int a = 0;
  73     ranges::for_each(y, [&a](int i) { a += i; }, &Y::i);
  74     return a;
  75   };
  76   static_assert(f() == 6);
  77 }
  78
  79 template<template<typename> typename wrapper>
  80 void
  81 test03()
  82 {
  83   int x[] = {1,2,3,4,5};
  84   test_range<int, wrapper> rx(x);
  85   int s = 0;
  86   auto func = [&s](int i){ s += i; };
  87   auto [i,f] = ranges::for_each_n(rx.begin(), 3, func);
  88   VERIFY( i.ptr = x+3 );
  89   VERIFY( s == 1+2+3 );
  90   f(1);
  91   VERIFY( s == 1+2+3+1 );
  92
  93   s = 0;
  94   rx.bounds.first = x;
  95   auto [j,g] = ranges::for_each_n(rx.begin(), -1, func);
  96   VERIFY( j.ptr == x );
  97   VERIFY( s == 0 );
  98   g(1);
  99   VERIFY( s == 1 );
 100
 101   s = 0;
 102   rx.bounds.first = x;
 103   auto [k,h] = ranges::for_each_n(rx.begin(), 5, func, std::negate<>{});
 104   VERIFY( k.ptr == x+5 );
 105   VERIFY( s == -(1+2+3+4+5) );
 106   h(-6);
 107   VERIFY( s == -(1+2+3+4+5+6) );
 108 }
 109
 110 constexpr bool
 111 test04()
 112 {
 113   int x[] = {1,2,3,4,5};
 114   int p = 1;
 115   ranges::for_each_n(x+1, 4, [&p](int i){ p*=i; }, [](int i){ return i+1; });
 116   return p == 3*4*5*6;
 117 }
 118
 119 int
 120 main()
 121 {
 122   test01();
 123   test02();
 124   test03<input_iterator_wrapper>();
 125   test03<random_access_iterator_wrapper>();
 126   static_assert(test04());
 127 }