Calculates the length of a null-terminated character sequence, that is, the smallest i such that p[i] == 0.

Standard library specializations of std::regex_traits execute std::char_traits<CharT>::length(p);.

Parameters

Return value

The length of the null-terminated character string.

Example

#include <iostream>
#include <regex>

int main()
{
    std::cout << std::regex_traits<char>::length("Кошка") << '\n'
              << std::regex_traits<wchar_t>::length(L"Кошка") << '\n';
}