libstdc++-v3/testsuite/23_containers/span/nothrow_cons.cc

   1 // Copyright (C) 2019-2025 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 compile { target c++20 } }
  19
  20 #include <span>
  21
  22 using std::span;
  23 using std::is_nothrow_constructible_v;
  24
  25 static_assert( is_nothrow_constructible_v<span<int>> );
  26 static_assert( is_nothrow_constructible_v<span<int, 0>> );
  27
  28 static_assert( is_nothrow_constructible_v<span<int>, span<int>&> );
  29 static_assert( is_nothrow_constructible_v<span<const int>, span<int>&> );
  30 static_assert( is_nothrow_constructible_v<span<int>, span<int, 1>&> );
  31 static_assert( is_nothrow_constructible_v<span<const int>, span<int, 1>&> );
  32 static_assert( is_nothrow_constructible_v<span<int, 1>, span<int, 1>&> );
  33 static_assert( is_nothrow_constructible_v<span<const int, 1>, span<int, 1>&> );
  34
  35 static_assert( is_nothrow_constructible_v<span<int>, int(&)[1]> );
  36 static_assert( is_nothrow_constructible_v<span<int, 1>, int(&)[1]> );
  37 static_assert( is_nothrow_constructible_v<span<int>, std::array<int, 1>&> );
  38 static_assert( is_nothrow_constructible_v<span<int, 1>, std::array<int, 1>&> );
  39
  40 template<bool>
  41 struct sentinel { int* p; };
  42
  43 template<bool B>
  44 bool operator==(sentinel<B> s, int* p) noexcept { return s.p == p; }
  45
  46 template<bool B>
  47 std::ptrdiff_t operator-(sentinel<B> s, int* p) noexcept(B) { return s.p - p; }
  48
  49 template<bool B>
  50 std::ptrdiff_t operator-(int* p, sentinel<B> s) noexcept { return p - s.p; }
  51
  52 static_assert(std::sized_sentinel_for<sentinel<true>, int*>);
  53 static_assert(std::sized_sentinel_for<sentinel<false>, int*>);
  54
  55 static_assert(is_nothrow_constructible_v<span<int>, int*, std::size_t>);
  56 static_assert(is_nothrow_constructible_v<span<int>, int*, const int*>);
  57 static_assert(is_nothrow_constructible_v<span<int>, int*, sentinel<true>>);
  58 static_assert(!is_nothrow_constructible_v<span<int>, int*, sentinel<false>>);