83 lines · cpp
1// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s2 3// This is heavily affected by the speculative resolution applied to CWG23114// So behaviour shown here is subject to change.5 6// expected-no-diagnostics7 8namespace std {9 typedef decltype(sizeof(int)) size_t;10 11 // libc++'s implementation12 template <class _E>13 class initializer_list14 {15 const _E* __begin_;16 size_t __size_;17 18 initializer_list(const _E* __b, size_t __s)19 : __begin_(__b),20 __size_(__s)21 {}22 23 public:24 typedef _E value_type;25 typedef const _E& reference;26 typedef const _E& const_reference;27 typedef size_t size_type;28 29 typedef const _E* iterator;30 typedef const _E* const_iterator;31 32 constexpr initializer_list() : __begin_(nullptr), __size_(0) {}33 34 constexpr size_t size() const {return __size_;}35 const _E* begin() const {return __begin_;}36 const _E* end() const {return __begin_ + __size_;}37 };38 39 template<typename T>40 struct vector {41 size_t sz;42 constexpr vector() : sz(0) {}43 constexpr vector(initializer_list<T> ilist) : sz(ilist.size()) {}44 constexpr vector(const vector& other) : sz(other.sz) {}45 constexpr std::size_t size() const { return sz; }46 };47}48 49// https://github.com/llvm/llvm-project/pull/77768#issuecomment-190806247250namespace Issue1 {51 struct A {52 constexpr A() {}53 };54 55 struct B {56 int called_ctor;57 constexpr explicit B(A) : called_ctor(0) {}58 constexpr explicit B(std::vector<A>) : called_ctor(1) {}59 };60 61 struct C {62 B b;63 constexpr C() : b({A()}) {}64 };65 66 static_assert(C().b.called_ctor == 0);67}68 69// https://github.com/llvm/llvm-project/pull/77768#issuecomment-195717180570namespace Issue2 {71 struct A {72 constexpr A(int x_) {}73 constexpr A(const std::vector<A>& a) {}74 };75 76 void f() {77 constexpr std::vector<A> a{1,2};78 constexpr std::vector<A> b{a};79 // -> constexpr std::vector<A> b(std::initializer_list<A>{ A(a) });80 static_assert(b.size() == 1);81 }82}83