Can a char* be moved into an std::string?

Say I have something like this

extern "C" void make_foo (char** tgt) {
  *tgt = (char*) malloc(4*sizeof(char));
  strncpy(*tgt, "foo", 4);
}

int main() {
  char* foo;
  make_foo(&foo);
  std::string foos;
  free(foo);
  ...
  return 0;
}

Now, I would like to avoid using and then deleting the foo buffer. I.e., I'd like to change the initialisation of foos to something like

  std::string foos;

and use no explicit free.

Turns out this actually compiles and seems to work, but I have a rather suspicious feel about it: does it actually move the C-defined string and properly free the storage? Or does it just ignore the std::move and leak the storage once the foo pointer goes out of scope?

It's not that I worry too much about the extra copy, but I do wonder if it's possible to write this in modern move-semantics style.