static TCHAR szWindowClass = L"foo";
L is not a macro, it's just the standard prefix for wide (
wchar_t, "Unicode") string literals; the concept is similar to the
L suffix for
long int literals,
f suffix for
float literals and so on1.
By the way, if you are using
TCHARs you shouldn't be using
L directly; instead, you should use the
TEXT() macro, that adds
L at the beginning of the literal if the application is compiled "for Unicode" (i.e.
TCHAR is defined as
WCHAR), or adds nothing if the compilation target is "ANSI" (
TCHAR defined as