or download this
Useless use of array element in void context at ./t2 line 30 (#1)
(W void) You did something without a side effect in a context that
+ does
nothing with the return value, such as a statement that doesn't re
+turn a
...
optimized into "that " . $foo, and the warning will refer to the
concatenation (.) operator, even though there is no . in
your program.