Standard library header <cctype>

From cppreference.com

This header was originally in the C standard library as <ctype.h>.

This header is part of the null-terminated byte strings library.

Functions

checks if a character is alphanumeric
(function)
checks if a character is alphabetic
(function)
checks if a character is lowercase
(function)
checks if a character is an uppercase character
(function)
checks if a character is a digit
(function)
checks if a character is a hexadecimal character
(function)
checks if a character is a control character
(function)
checks if a character is a graphical character
(function)
checks if a character is a space character
(function)
(C++11)
checks if a character is a blank character
(function)
checks if a character is a printing character
(function)
checks if a character is a punctuation character
(function)
converts a character to lowercase
(function)
converts a character to uppercase
(function)