table of contents
std::ctype::is(3) | C++ Standard Libary | std::ctype::is(3) |
NAME¶
std::ctype::is - std::ctype::is
Synopsis¶
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] & m
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()
2) high
Notes¶
Unlike the primary template std::ctype, this specialization does
not perform a
virtual function call when classifying characters. To customize the behavior,
a
derived class may provide a non-default classification table to the base
class
constructor.
Example¶
This section is incomplete
Reason: no example
See also¶
do_is classifies a character or a character sequence
[virtual] (virtual protected member function of
std::ctype<CharT>)
2022.07.31 | http://cppreference.com |