C++ convert string to size_t

To convert a string to size_t in C++, you can use the std::stoull function. Here's an example:

#include <iostream>
#include <string>

int main() {
    std::string str = "12345";
    size_t num = std::stoull(str);
    std::cout << "Converted value: " << num << std::endl;
    return 0;
}

In this example, the std::stoull function is used to convert the string "12345" to a size_t variable num. The converted value is then printed using std::cout.