1 // RUN: clang-cc -E %s | grep '^"x ## y";$'
2 #define hash_hash # ## #
3 #define mkstr(a) # a
4 #define in_between(a) mkstr(a)
5 #define join(c, d) in_between(c hash_hash d)
6 join(x, y);
7 
8