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

   1 // Copyright (C) 2019-2023 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 <ranges>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_iterators.h>
  24
  25 static_assert(__gnu_test::is_customization_point_object(std::ranges::cdata));
  26
  27 template<typename T>
  28   concept has_cdata
  29     = requires (T&& t) { std::ranges::cdata(std::forward<T>(t)); };
  30
  31 void
  32 test01()
  33 {
  34   struct R
  35   {
  36     int i = 0;
  37     int j = 0;
  38     int* data() { return &j; }
  39     const R* data() const noexcept { return nullptr; }
  40   };
  41   static_assert( has_cdata<R&> );
  42   static_assert( has_cdata<const R&> );
  43   R r;
  44   const R& c = r;
  45   VERIFY( std::ranges::cdata(r) == (R*)nullptr );
  46   static_assert( noexcept(std::ranges::cdata(r)) );
  47   VERIFY( std::ranges::cdata(c) == (R*)nullptr );
  48   static_assert( noexcept(std::ranges::cdata(c)) );
  49
  50   // not lvalues and not borrowed ranges
  51   static_assert( !has_cdata<R> );
  52   static_assert( !has_cdata<const R> );
  53 }
  54
  55 void
  56 test02()
  57 {
  58   int a[] = { 0, 1 };
  59   VERIFY( std::ranges::cdata(a) == a + 0 );
  60
  61   static_assert( has_cdata<int(&)[2]> );
  62   static_assert( !has_cdata<int(&&)[2]> );
  63 }
  64
  65 struct R3
  66 {
  67   static inline int i = 0;
  68   static inline long l = 0;
  69
  70   int* data() &; // this function is not defined
  71   friend long* begin(R3&& r); // not defined
  72   friend const long* begin(const R3& r) { return &r.l; }
  73   friend const short* begin(const R3&&); // not defined
  74 };
  75
  76 template<> constexpr bool std::ranges::enable_borrowed_range<R3> = true;
  77
  78 void
  79 test03()
  80 {
  81   static_assert( has_cdata<R3&> );
  82   static_assert( has_cdata<R3> );  // borrowed range
  83   static_assert( has_cdata<const R3&> );
  84   static_assert( has_cdata<const R3> );  // borrowed range
  85
  86   R3 r;
  87   const R3& c = r;
  88   VERIFY( std::ranges::cdata(r) == std::ranges::data(c) );
  89   VERIFY( std::ranges::cdata(std::move(r)) == std::ranges::data(c) );
  90   VERIFY( std::ranges::cdata(std::move(c)) == std::ranges::begin(c) );
  91 }
  92
  93 int
  94 main()
  95 {
  96   test01();
  97   test02();
  98   test03();
  99 }