std::basic_string_view::front

From cppreference.com
constexpr const_reference front() const;
(since C++17)

Returns reference to the first character in the view. The behavior is undefined if empty() == true.

Parameters

(none)

Return value

reference to the first character, equivalent to operator[](0).

Complexity

Constant.

See also

accesses the last character
(public member function)
checks whether the view is empty
(public member function)