std::initializer_list<T>::size
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                    |   size_type size() const noexcept;  | 
 (since C++11)  (until C++14)  | 
|
|   constexpr size_type size() const noexcept;  | 
(since C++14) | |
Returns the number of elements in the initializer list, i.e. std::distance(begin(), end()).
Parameters
(none)
Return value
the number of elements in the initializer list
Complexity
Constant