The example below should work identically with and without compiler native wchar_t support.
void foo(wchar_t * t = L"");
Can you add some negative tests like these:
short *p1 = L""; // error
int *p2 = L""; // error
Even if they don't make it into IsStringLiteralToNonConstPointerConversion, it's nice to test around things a bit.
I added few more negative tests. Thank you for the review!