I learned today that there are digraphs in C99 and C++. The following is a valid program:
%:define BUFSIZE 512
void copy(char d<::>, const char s<::>, int len)
while (len-- >= 0)
d<:len:> = s<:len:>;
Digraphs were created for programmers that didn't have a keyboard which supported the ISO 646 character set.