std::ctype<char>::scan_is
| Defined in header <locale>
|
||
| const char* scan_is (mask m, const char* beg, const char* end) const; |
(1) | |
Locates the first character in the character array [beg, end) that satisfies the classification mask m, that is, the first character c such that table()[(unsigned char) c] & m would return true.
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
| m | - | mask to search for |
| beg | - | pointer to the first character in an array of characters to search |
| end | - | one past the end pointer for the array of characters to search |
Return value
Pointer to the first character in [beg, end) that satisfies the mask, or end if no such character was found.
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
#include <locale> #include <iostream> #include <iterator> int main() { auto& f = std::use_facet<std::ctype<char>>(std::locale("")); // skip until the first letter char s1[] = " \t\t\n Test"; const char* p1 = f.scan_is(std::ctype_base::alpha, std::begin(s1), std::end(s1)); std::cout << "'" << p1 << "'\n"; // skip until the first letter char s2[] = "123456789abcd"; const char* p2 = f.scan_is(std::ctype_base::alpha, std::begin(s2), std::end(s2)); std::cout << "'" << p2 << "'\n"; }
Output:
'Test' 'abcd'
See also
| [virtual] |
locates the first character in a sequence that conforms to given classification (virtual protected member function of std::ctype) |
| locates the first character in a sequence that fails given classification, using the classification table (public member function) |