/in/foo.c: In function 'concat':
/in/foo.c:5:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
 {
 ^
/in/foo.c:13:1: error: expected '{' at end of input
 }
 ^
/in/foo.c:13:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^