std::ctype<char>::scan_not

From cppreference.com
< cpp‎ | locale‎ | ctype char
Defined in header <locale>
const char * scan_not( mask m, const char * beg, const char * end ) const ;

Locates the first character in the character array [ beg end ) that does not satisfy the classification mask m, that is, the first character c such that table( ) [ ( unsigned char )c] & would return false

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 does not satisfy the mask, or end

Notes

Unlike the primary template std::ctype

Example

#include <iostream>
#include <iterator>
#include <locale>
 
int main()
{
    auto& f = std::use_facet<std::ctype<char>>(std::locale());
 
    // skip leading whitespace
    char s1[] = "      \t\t\n  Test";
    const char* p1 = f.scan_not(std::ctype_base::space, std::begin(s1), std::end(s1));
    std::cout << '\'' << p1 << "'\n";
 
    // skip leading digits
    char s2[] = "123456789abcd";
    const char* p2 = f.scan_not(std::ctype_base::digit, std::begin(s2), std::end(s2));
    std::cout << '\'' << p2 << "'\n";
}

Output:

'Test'
'abcd'

See also

[virtual]
locates the first character in a sequence that fails given classification
(virtual protected member function of std::ctype<CharT>)
locates the first character in a sequence that conforms to given classification, using the classification table
(public member function)