我将代码从头文件initializer_list
中复制,并将类名改为my_initializer_list
template<class _E>
class my_initializer_list
{
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;
private:
iterator _M_array;
size_type _M_len;
// The compiler can call a private constructor.
constexpr my_initializer_list(const_iterator __a, size_type __l)
: _M_array(__a), _M_len(__l) { }
public:
constexpr my_initializer_list() noexcept
: _M_array(0), _M_len(0) { }
// Number of elements.
constexpr size_type
size() const noexcept { return _M_len; }
// First element.
constexpr const_iterator
begin() const noexcept { return _M_array; }
// One past the last element.
constexpr const_iterator
end() const noexcept { return begin() + size(); }
};
以及代码:
int main()
{
my_initializer_list<int> foo = {1,2,3};
return 0;
}
而且收到了错误提示:
could not convert '{1, 2, 3}' from '<brace-enclosed initializer list>' to 'my_initializer_list<int>'
我的问题:STL是如何实现initializer_list类的?
std::typeinfo
的定义,然后使用typeid
来获取一个。 - user253751