std::regex_traits::length

From cppreference.com


static std::size_t length(const char_type* p);

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);

[edit] Parameters

p

-

pointer to the first element of the null-terminated character sequence

[edit] Return value

The length of the null-terminated character string.

[edit] Example

run this code

#include <regex>
#include <iostream>
 
int main()
{
    std::cout << std::regex_traits<char>::length(u8"Кошка") << '\n'
              << std::regex_traits<wchar_t>::length(L"Кошка") << '\n';
}

Output:

10
5

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)