libstdc++-v3/testsuite/std/ranges/access/cdata.cc

   1 // Copyright (C) 2019-2020 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 <ranges>
  22 #include <testsuite_hooks.h>
  23
  24 void
  25 test01()
  26 {
  27   struct R
  28   {
  29     int i = 0;
  30     int j = 0;
  31     int* data() { return &j; }
  32     const R* data() const noexcept { return nullptr; }
  33   };
  34   R r;
  35   const R& c = r;
  36   VERIFY( std::ranges::cdata(r) == (R*)nullptr );
  37   static_assert( noexcept(std::ranges::cdata(r)) );
  38   VERIFY( std::ranges::cdata(c) == (R*)nullptr );
  39   static_assert( noexcept(std::ranges::cdata(c)) );
  40 }
  41
  42 void
  43 test02()
  44 {
  45   int a[] = { 0, 1 };
  46   VERIFY( std::ranges::cdata(a) == a + 0 );
  47 }
  48
  49 struct R
  50 {
  51   long l = 0;
  52
  53   int* data() const { return nullptr; }
  54   friend long* begin(R&& r); // this function is not defined
  55   friend const long* begin(const R& r) { return &r.l; }
  56   friend const short* begin(const R&&); // not defined
  57 };
  58
  59 // This is a lie, ranges::begin(R&&) returns a dangling iterator.
  60 template<> constexpr bool std::ranges::enable_safe_range<R> = true;
  61
  62 void
  63 test03()
  64 {
  65   R r;
  66   const R& c = r;
  67   VERIFY( std::ranges::cdata(r) == std::ranges::data(c) );
  68   VERIFY( std::ranges::cdata(std::move(r)) == std::ranges::begin(c) );
  69   VERIFY( std::ranges::cdata(std::move(c)) == std::ranges::begin(c) );
  70 }
  71
  72 int
  73 main()
  74 {
  75   test01();
  76   test02();
  77   test03();
  78 }