[cctype.syn]

# 28 Text processing library [[text]](./#text)

## 28.7 Null-terminated sequence utilities [[text.c.strings]](text.c.strings#cctype.syn)

### 28.7.1 Header <cctype> synopsis [cctype.syn]

[ð](#lib:isalnum)

namespace std {int isalnum(int c); int isalpha(int c); int isblank(int c); int iscntrl(int c); int isdigit(int c); int isgraph(int c); int islower(int c); int isprint(int c); int ispunct(int c); int isspace(int c); int isupper(int c); int isxdigit(int c); int tolower(int c); int toupper(int c);}

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L13029)

The contents and meaning of the header <cctype> are the same as the C standard library header [<ctype.h>](support.c.headers.general#header:%3cctype.h%3e "17.15.1 General [support.c.headers.general]")[.](#1.sentence-1)

See also: ISO/IEC 9899:2024, 7.4
