evaluation order initialization array in c++

Question

I like c++11 variadic templates, so I often write some little codes with it.

See this example:

#include 
#include 
#         


        

Answer 1

They are evaluated sequentially. C++11 § 8.5.4 [dcl.init.list] paragraph 4:

Within the initializer-list of a braced-init-list, the initializer-clauses, including any that result from pack expansions (14.5.3), are evaluated in the order in which they appear.

Given that vector has an initializer_list constructor, you could simplify your function to:

template <typename ... T>
auto make_vector(T ... t) ->
  std::vector< typename std::common_type<T...>::type >
{
  return { static_cast<typename std::common_type<T...>::type>(t)... };
}

and not have to worry about arcane initialization semantics ;)