std::basic_string<CharT,Traits,Allocator>:: find_first_not_of

Finds the first character equal to none of the characters in the given character sequence. The search considers only the range [ pos , size() ) . If all characters in the range can be found in the given character sequence, npos will be returned.

In all cases, equality is checked by calling Traits::eq .

Parameters

Return value

Position of the found character or std::string::npos if no such character is found.

Exceptions

If an exception is thrown for any reason, this function has no effect ( strong exception safety guarantee ).

Example

#include <iostream>
#include <string>
 
int main()
{
    // Permit uppercase letters, lowercase letters and numbers in macro names
    const char* pattern = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                          "abcdefghijklmnopqrstuvwxyz"
                          "0123456789";
 
    std::string data = "1) %FIX, 2) %HACK, and 3) %TODO";
    const std::string replacement = "%DONE%";
 
    std::cout << "Before: " << data << '\n';
 
    for (std::string::size_type first{}, last{};
        (first = data.find('%', first)) != std::string::npos;
        first += replacement.size())
    {
        last = data.find_first_not_of(pattern, first + 1);
        if (last == std::string::npos)
            last = data.length();
 
        // Now first at '%' and last is one past end of the found substring
        data.replace(first, last - first, replacement);
    }
 
    std::cout << "After: " << data << '\n';
}

Before: 1) %FIX, 2) %HACK, and 3) %TODO
After: 1) %DONE%, 2) %DONE%, and 3) %DONE%

Defect reports

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

See also