How to emulate C array initialization “int arr[] = { e1, e2, e3, … }” behaviour with std::array?

by

Best I can think of is:

template<class T, class... Tail>
auto make_array(T head, Tail... tail) -> std::array<T, 1 + sizeof...(Tail)>
{
     std::array<T, 1 + sizeof...(Tail)> a = { head, tail ... };
     return a;
}

auto a = make_array(1, 2, 3);

However, this requires the compiler to do NRVO, and then also skip the copy of returned value (which is also legal but not required). In practice, I would expect any C++ compiler to be able to optimize that such that it’s as fast as direct initialization.

More Related Contents:

  1. How to initialize std::array elegantly if T is not default constructible?
  2. C++11: Correct std::array initialization?
  3. Now that we have std::array what uses are left for C-style arrays?
  4. too many initializers for ‘int [0]’ c++
  5. Interfacing C++11 array with Cython
  6. Is there a way to statically-initialize a dynamically-allocated array in C++?
  7. Optimization code for a debug function (c++11 with templates) [closed]
  8. C++11 does not deduce type when std::function or lambda functions are involved
  9. initializer_list and move semantics
  10. Can someone explain this template code that gives me the size of an array? [duplicate]
  11. What are the differences between C-like, constructor, and uniform initialization?
  12. How to convert a lambda to an std::function using templates
  13. How does this “size of array” template function work? [duplicate]
  14. static_assert fails compilation even though template function is called nowhere
  15. trailing return type using decltype with a variadic template function
  16. Selecting a member function using different enable_if conditions
  17. Calling a function for each variadic template argument and an array
  18. How does the range-based for work for plain arrays?
  19. Range-based for loop on a dynamic array?
  20. C++11 member initializer list vs in-class initializer?
  21. Expansion with variadic templates [duplicate]
  22. What is the easiest way to print a variadic parameter pack using std::ostream?
  23. Variadic function template with pack expansion not in last parameter
  24. Default template argument when using std::enable_if as templ. param.: why OK with two template functions that differ only in the enable_if parameter?
  25. How does std::end know the end of an array?
  26. Is std::array movable?
  27. Why the initializer of std::function has to be CopyConstructible?
  28. gcc can compile a variadic template while clang cannot
  29. Specialized template function with deleted “general” case fails to compile with g++
  30. How does std::forward receive the correct argument?

Leave a Comment