Bug 1196 – regression: "cannot alias an expression"

This is an interresting case because small - and seemingly unrelated changes - can cause the message to vanish: # template removeSpace(char[] s, int x = 0) { # static if (s[0] == ' '){ # alias removeSpace!(s[1..$], x+1) removeSpace; # }else{ # alias s removeSpace; # } # } # # struct Tuple(A...) { # alias A Tuple; # } # static assert("Hello you !" == removeSpace!(" Hello you !")); compile/t/tuple_21_B.d(14): alias dstress.compile.t.tuple_21_B.removeSpace!(" Hello you !",6).removeSpace cannot alias an expression "Hello you !" # static assert("Hello you !" == removeSpace!(" Hello you !").Tuple[0]); succeeds test cases: http://dstress.kuehne.cn/nocompile/t/template_21_A.d http://dstress.kuehne.cn/nocompile/t/template_21_B.d http://dstress.kuehne.cn/run/template_12.d

Both examples fail when I try it with the same error message. The error message is correct - an alias cannot be made of an expression (in this case, a string literal). A working example would be: template removeSpace(char[] s, int x = 0) { static if (s[0] == ' '){ const char[] removeSpace = removeSpace!(s[1..$], x+1); }else{ const char[] removeSpace = s; } } struct Tuple(A...) { alias A Tuple; } static assert("Hello you !" == removeSpace!(" Hello you !"));