std::ctype::scan_not, std::ctype::do_scan_not

Defined in header <locale>
const CharT* scan_not( mask m, const CharT* beg, const CharT* end ) const;
virtual const CharT* do_scan_not( mask m, const CharT* beg, const CharT* end) const;
1) public member function, calls the protected virtual member function do_scan_not of the most derived class.
2) 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 is(m, c) would return false.


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 doesn't satisfy the mask, or end if no such character was found.


#include <locale>
#include <iostream>
#include <iterator>
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";



See also

locates the first character in a sequence that conforms to given classification
(virtual protected member function)

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