It's very hard to twist what the OP has into something that's a problem, so I guess you're just providing trivia. In that case, let me add that any lvalue context will suffice.

>perl -E"@a[4..99] = ();  say 0+@a;"
100

>perl -E"for (@a[4..99]) {}  say 0+@a;"
100

>perl -E"sub {}->(@a[4..99]);  say 0+@a;"
100

>perl -E"grep 1, @a[4..99];  say 0+@a;"
100
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