string representing date and transform it

Question

To format a string representing date received from other part some transform is required:

source:
    std::string s = "20190510";
target:
    std::string t = "05/10/2019";

One way is to copy char by char, is there an elegant way to do it beautiful and fast?

UPDATE: Sorry the transform should be from "yyyymmdd" to "mm/dd/yyyy".

Answer 1

Try insert:

int main() {
    std::string s = "20190510";
    s.insert(4, "/");
    s.insert(7, "/");
    std::cout << s << std::endl;
}