Iterate over a std::string and pull out chars and ints

Question

I'm looking to iterate over a string like this:

string mystr = "13n4w14n3w2s";

What I am looking to pull out is sort of a map if possible from that string but keep the order in which it is found.

13 n
4 w
14 n
3 w
2 s

For which I'll iterate over at, at another point in time. Now I've seen examples of pulling values out of a simple string like "13a"

string str = "13a";
int num;
char dir;

str >> num >> dir;

How can I do something similar to the longer string at the top?

Answer 1

You could use std::istringstream and loop and read from the stream like this:

std::string mystr = "13n4w14n3w2s";
std::istringstream iss{mystr};
std::vector<std::pair<int, char>> mappings; // To store the int-char pairs.
int num;
char dir;
while (iss >> num >> dir) {
    std::cout << num << std::endl;   // Next int from the stream.
    std::cout << dir << std::endl;   // Next char from the stream.
    mappings.emplace_back(num, dir); // Store the pair.
}

Here is a link to a demo on ideone.