Change the current working directory in C++

How can I change my current working directory in C++ in a platform-agnostic way?

I found the direct.h header file, which is Windows compatible, and the unistd.h, which is UNIX/POSIX compatible.

The chdir function works on both POSIX (manpage) and Windows (called _chdir there but an alias chdir exists).

Both implementations return zero on success and -1 on error. As you can see in the manpage, more distinguished errno values are possible in the POSIX variant, but that shouldn't really make a difference for most use cases.

Now, with C++17 is possible to use std::filesystem::current_path:

#include <filesystem>
int main() {
    auto path = std::filesystem::current_path(); //getting path
    std::filesystem::current_path(path); //setting path
}