clang/test/AST/ByteCode/initializer_list.cpp

   1 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -fms-extensions -std=c++20 -verify=expected,both %s
   2 // RUN: %clang_cc1 -std=c++20 -fms-extensions -verify=ref,both %s
   3
   4 namespace std {
   5   typedef decltype(sizeof(int)) size_t;
   6   template <class _E>
   7   class initializer_list
   8   {
   9     const _E* __begin_;
  10     size_t    __size_;
  11
  12     initializer_list(const _E* __b, size_t __s)
  13       : __begin_(__b),
  14         __size_(__s)
  15     {}
  16
  17   public:
  18     typedef _E        value_type;
  19     typedef const _E& reference;
  20     typedef const _E& const_reference;
  21     typedef size_t    size_type;
  22
  23     typedef const _E* iterator;
  24     typedef const _E* const_iterator;
  25
  26     constexpr initializer_list() : __begin_(nullptr), __size_(0) {}
  27
  28     constexpr size_t    size()  const {return __size_;}
  29     constexpr const _E* begin() const {return __begin_;}
  30     constexpr const _E* end()   const {return __begin_ + __size_;}
  31   };
  32 }
  33
  34 class Thing {
  35 public:
  36   int m = 12;
  37   constexpr Thing(int m) : m(m) {}
  38   constexpr bool operator==(const Thing& that) const {
  39     return this->m == that.m;
  40   }
  41 };
  42
  43 constexpr bool is_contained(std::initializer_list<Thing> Set, const Thing &Element) {
  44    return (*Set.begin() == Element);
  45 }
  46
  47 constexpr int foo() {
  48   const Thing a{12};
  49   const Thing b{14};
  50   return is_contained({a}, b);
  51 }
  52
  53 static_assert(foo() == 0);
  54
  55
  56 namespace rdar13395022 {
  57   struct MoveOnly { // both-note {{candidate}}
  58     MoveOnly(MoveOnly&&); // both-note 2{{copy constructor is implicitly deleted because}} both-note {{candidate}}
  59   };
  60
  61   void test(MoveOnly mo) {
  62     auto &&list1 = {mo}; // both-error {{call to implicitly-deleted copy constructor}} both-note {{in initialization of temporary of type 'std::initializer_list}}
  63     MoveOnly (&&list2)[1] = {mo}; // both-error {{call to implicitly-deleted copy constructor}} both-note {{in initialization of temporary of type 'MoveOnly[1]'}}
  64     std::initializer_list<MoveOnly> &&list3 = {};
  65     MoveOnly (&&list4)[1] = {}; // both-error {{no matching constructor}}
  66     // both-note@-1 {{in implicit initialization of array element 0 with omitted initializer}}
  67     // both-note@-2 {{in initialization of temporary of type 'MoveOnly[1]' created to list-initialize this reference}}
  68   }
  69 }
  70
  71