libstdc++-v3/testsuite/25_algorithms/copy_n/5.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++11 } }
  19
  20 #include <algorithm>
  21 #include <testsuite_iterators.h>
  22
  23 void
  24 test01()
  25 {
  26   // Negative sizes should be a no-op
  27
  28   const int from[2] = { 1, 2 };
  29   __gnu_test::input_container<const int> f(from);
  30   int* to = nullptr;
  31   std::copy_n(f.begin(), -1, to);
  32
  33   std::copy_n(from, -20000, to); // random access
  34
  35   __gnu_test::random_access_container<const int> f2(from);
  36   std::copy_n(f2.end(), -1, to);
  37   std::copy_n(f2.begin(), -1, to);
  38 }
  39
  40 struct Size
  41 {
  42   operator long() const { return 2L; }
  43
  44   void operator++() = delete;
  45   void operator--() = delete;
  46   void operator++(int) = delete;
  47   void operator--(int) = delete;
  48
  49   template<typename T> friend void operator+(Size, T) = delete;
  50   template<typename T> friend void operator+(T, Size) = delete;
  51   template<typename T> friend void operator-(Size, T) = delete;
  52   template<typename T> friend void operator-(T, Size) = delete;
  53   template<typename T> friend void operator==(Size, T) = delete;
  54   template<typename T> friend void operator==(T, Size) = delete;
  55   template<typename T> friend void operator!=(Size, T) = delete;
  56   template<typename T> friend void operator!=(T, Size) = delete;
  57   template<typename T> friend void operator<(Size, T) = delete;
  58   template<typename T> friend void operator<(T, Size) = delete;
  59   template<typename T> friend void operator<=(Size, T) = delete;
  60   template<typename T> friend void operator<=(T, Size) = delete;
  61   template<typename T> friend void operator>(Size, T) = delete;
  62   template<typename T> friend void operator>(T, Size) = delete;
  63   template<typename T> friend void operator>=(Size, T) = delete;
  64   template<typename T> friend void operator>=(T, Size) = delete;
  65 };
  66
  67 void
  68 test02()
  69 {
  70   // C++20 only requires that Size is convertible to an integral type,
  71   // it doesn't need to support any arithmetic or relational expressions.
  72
  73   const int from[3] = { 1, 2, 3 };
  74   __gnu_test::input_container<const int> f(from);
  75   int to[3] = { };
  76   __gnu_test::output_container<int> t(to);
  77   Size s;
  78   std::copy_n(f.begin(), s, t.begin());
  79   VERIFY( to[0] == 1 );
  80   VERIFY( to[1] == 2 );
  81   VERIFY( to[2] == 0 );
  82
  83   const int from2[3] = { 11, 22, 33 };
  84   __gnu_test::random_access_container<const int> f2(from2);
  85   __gnu_test::output_container<int> t2(to);
  86   std::copy_n(f2.begin(), s, t2.begin());
  87   VERIFY( to[0] == 11 );
  88   VERIFY( to[1] == 22 );
  89   VERIFY( to[2] == 0 );
  90 }
  91
  92 int
  93 main()
  94 {
  95   test01();
  96   test02();
  97 }