How to correctly find the length of a Cyrillic string in Unicode in C++?

Question

C++ / C#

How to correctly calculate the length of a string with Russian letters, punctuation marks and spaces?
So far, I found that the length of the string with rbhbkkbwtq turns out to be twice the correct one.

int strLength = strBody.length();
std::cout << strBody << ":" << strLength ;

...

Ololo:5
Ололо:10

Answer 1

If under Linux, then somehow you can calculate like this:

#include <cstdlib>
//....
setlocale(LC_ALL, "ru_RU.utf8");
int strLength = mbstowcs(NULL, strBody.c_str(), 0);

Unfortunately, this won't work on Windows.

Answer 2

So far, I found that the length of the string with Russian letters is twice as long as the correct one.

Pusho UTF-8 encoding.
Although the length of the string should be the same, it's more about the size in memory.