std::ctype<char>::is

From cppreference.com
< cpp‎ | locale‎ | ctype char
C++
Text processing library
Localization library
std::ctype
Defined in header <locale>
bool is( mask m, char c ) const;
 (1)
const char * is( const char * low, const char * high, mask* vec ) const ;
(2)
1) Checks if the character c is classified by the mask m according to the classification table returned by the member function table(). Effectively calculates table( ) [ ( unsigned char )c] &
2) For every character in the character array [ low ,  high ) , reads its full classification mask from the classification table returned by the member function table() (that is, evaluates table( ) [ ( unsigned char ) *p] and stores it in the corresponding element of the array pointed to by vec

If ( unsigned char )c >= std::ctype < char > :: table_size , then an implementation-defined value is substituted instead of table( ) [ ( unsigned char )c] , possibly different for different values of c

Parameters

c - character to classify
m - mask to use for classifying a single character
low - pointer to the first character in an array of characters to classify
high - one past the end pointer for the array of characters to classify
vec - pointer to the first element of the array of masks to fill

Return value

1) true if c is classified by m in table(), false
2) high

Notes

Unlike the primary template std::ctype

Example

This section is incomplete
Reason: no example

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 28 C++98 overload (2) copied the values from vec into table(),
 corrected

See also

[virtual]
 classifies a character or a character sequence
(virtual protected member function of std::ctype<CharT>)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/locale/ctype_char/is&oldid=160073