Nonsense! Not every OS uses the forward slash (/) as path separator.

So what, the OP doesn't have one of those

On a classic, non-X MacOS, you will fail miserably because MacOS uses single colons (:).

No you won't, you'll get a nice error message, and then you cheerfully fix it -- or it will cheerfully work and you'll get a file with slashes in the name -- no misery anywhere

Same game, different rules with VMS ...

Same ol' same ol'

File::Spec is not perfect, but it still is better than simply using the forward slash everywhere.

File::Spec is great, Path::Class is better, but using forward slashes on unix/linux/windows will work 99% of the time