我尝试实现C++ 14别名模板make_integer_sequence,这简化了类模板的创建integer_sequence.
template< class T, T... I> struct integer_sequence
{
typedef T value_type;
static constexpr size_t size() noexcept { return sizeof...(I) ; }
};
template< class T, T N>
using make_integer_sequence = integer_sequence< T, 0,1,2, ... ,N-1 >; // only for illustration.
为了实现,make_integer_sequence我们需要一个辅助结构make_helper.
template< class T , class N >
using make_integer_sequence = typename make_helper<T,N>::type;
实施make_helper并不太难.
template< class T, T N, T... I >
struct make_helper
{
typedef …