Text processing library

The text processing library includes components for dealing with text.

Localization library

The headers <locale> and <clocale> provide internationalization support for character classification and string collation, numeric, monetary, and date/time formatting and parsing, and message retrieval.

Regular expressions library (since C++11)

The header <regex> provides a class that represents regular expressions, which are a kind of mini-language used to perform pattern matching within strings.

Formatting library (since C++20)

The header <format> provides facilities for type-safe and extensible string formatting that is an alternative to the printf family of functions, and intended to complement the existing C++ I/O streams library.

Null-terminated sequence utilities

Null-terminated character sequences (NTCTS) are sequences of characters that are terminated by a null character (the value after value-initialization).

The strings library provides functions to create, inspect, and modify such sequences:

null-terminated byte strings (NTBS) helper functions (including support of wide character types),
null-terminated multibyte strings (NTMBS) helper functions.

Primitive numeric conversions (since C++17)

In addition to sophisticated locale-dependent parsers and formatters provided by the C++ I/O library, the C I/O library, C++ string converters, and C string converters, the header <charconv> provides light-weight, locale-independent, non-allocating, non-throwing parsers and formatters for arithmetic types.

Defined in header `<charconv>`
to_chars (C++17)	converts an integer or floating-point value to a character sequence (function)
to_chars_result (C++17)	the return type of `std::to_chars` (class)
from_chars (C++17)	converts a character sequence to an integer or floating-point value (function)
from_chars_result (C++17)	the return type of `std::from_chars` (class)
chars_format (C++17)	specifies formatting for `std::to_chars` and `std::from_chars` (enum)

Text encoding identifications (since C++26)

Defined in header `<text_encoding>`
text_encoding (C++26)	describes an interface for accessing the IANA Character Sets registry (class)