21 Language support library [language.support]

21.9 Initializer lists [support.initlist]

21.9.3 Initializer list access [support.initlist.access]

constexpr const E* begin() const noexcept;

Returns: A pointer to the beginning of the array. If size() == 0 the values of begin() and end() are unspecified but they shall be identical.

constexpr const E* end() const noexcept;

Returns: begin() + size().

constexpr size_t size() const noexcept;

Returns: The number of elements in the array.

Complexity: Constant time.