There's no processing. L"\x03A9"
is simply an array wchar_t const[2]
consisting of the two elements 0x3A9
and 0
, and similarly L"\xA9\x03"
is an array wchar_t const[3]
.
Note in particular C11 6.4.4.4/7:
Each octal or hexadecimal escape sequence is the longest sequence of characters that can constitute the escape sequence.
And also C++11 2.14.3/4:
There is no limit to the number of digits in a hexadecimal sequence.
Note also that when you are using a hexadecimal sequence, it is your responsibility to ensure that your data type can hold the value. C11-6.4.4.4/9 actually spells this out as a requirement, whereas in C++ exceeding the type's range is merely "implementation-defined". (And a good compiler should warn you if you exceed the type's range.)
Your code doesn't make sense, though, because the left-hand sides are neither arrays nor pointers. It should be like this:
wchar_t const * p = L"\x03A9"; // pointer to the first element of a string
wchar_t arr1[] = L"\x03A9"; // an actual array
wchar_t arr2[2] = L"\x03A9"; // ditto, but explicitly typed
std::wstring s = L"\x03A9"; // C++ only
On a tangent: This question of mine elaborates a bit on string literals and escape sequences.