print all file names in directory cpp

Sure, here is a response to your question:

#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;

int main() {
    for (const auto & entry : fs::directory_iterator("path_to_directory")) {
        if (entry.path().extension() == ".cpp") {
            std::cout << entry.path().filename() << std::endl;
        }
    }
    return 0;
}