Arguments for indexOf() and operator==()

Our testing shows that we can pass a char* to indexOf() and it works
correctly. But in the  ICU2.6 documentation I have found, I do not see a
indexOf() that takes a char*.  Can someone explain why indexOf(char*)
works, I would expect a compile error.  For example:
UnicodeString utext = "abcdefgh";
index = utext.indexOf("de");  //compiles and runs correctly, why?

We see similar behavior for operator==() although the only operator== I see
is:
UBool UnicodeString::operator==( const UnicodeString & text) const [inline]

Thanks,
Brad A. Forrest