12. String Views

A string view is a non-owning reference to a string. It represents a view of a sequence of characters. This sequence of characters can be a C++-string or a C-string. A string view needs the header <string_view>.

A string view is a for copying optimised string

From a birds-eye perspective the purpose of std::string_view is to avoid copying data which is already owned by someone else and to allow immutable access to a std::string like object. The string view is a kind of a restricted string that supports only the immutable operations. Additionally, a string view sv has two additional mutating operations: sv.remove_prefix and sv.remove_suffix.

String views are class templates parameterised by their character and their character trait. The character trait has a default. In contrast to a string, a string view is non-owner and, therefore, needs no allocator.

template<
    class CharT,
    class Traits = std::char_traits<CharT>
> class basic_string_view...