llvm-project/clang/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist-pr12086.cpp

// RUN: %clang_cc1 -std=c++11 -emit-llvm -o - -verify %s

namespace std {
  typedef decltype(sizeof(int)) size_t;

  // libc++'s implementation
  template <class _E>
  class initializer_list
  {
    const _E* __begin_;
    size_t    __size_;

    initializer_list(const _E* __b, size_t __s)
      : __begin_(__b),
        __size_(__s)
    {}

  public:
    typedef _E        value_type;
    typedef const _E& reference;
    typedef const _E& const_reference;
    typedef size_t    size_type;

    typedef const _E* iterator;
    typedef const _E* const_iterator;

    initializer_list() : __begin_(nullptr), __size_(0) {}

    size_t    size()  const {return __size_;}
    const _E* begin() const {return __begin_;}
    const _E* end()   const {return __begin_ + __size_;}
  };
}

std::initializer_list<std::initializer_list<int>> pleasefail = {
  {1, 2}, {3, 4}, {5, 6} // expected-error {{cannot compile}}
};