Di/Trigraphs not handled

Qt Creator doesn't understand di- and trigraphs.
E.g. This:

#include <iostream>

int main() <%
int a??(10:>;
std::cout << "a??(bc\n";
return 0;
??>

is a valid c++ program.
(in newer g++ versions trigraphs are disabled per default, but digraphs are still enabled)