Re: Ampersands and sub speed

I think the reason is because calling a function with & preserves the existing @_, so perl doesn't have to mess with the argument stack. In other words, &function; is a kind-of fancy goto.

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Re^2: Ampersands and sub speed by diotalevi (Canon) on Oct 14, 2005 at 21:43 UTC
No... goto() doesn't return to the next statement. This is a fancy way of saying function( @_ ).	[reply]
Re^3: Ampersands and sub speed by ambrus (Abbot) on Oct 15, 2005 at 12:39 UTC
Closer, but they're still not the same. This code works, `sub f { &g; print @_; } sub g { $_[0] .= "o, w"; push @_, "orld\n"; } +f($x = "hell");` [download] but if you change it like this, it breaks: `sub f { g(@_); print @_; } sub g { $_[0] .= "o, w"; push @_, "orld\n"; + } f($x = "hell");` [download]	[reply] [d/l] [select]
Re^4: Ampersands and sub speed by diotalevi (Canon) on Oct 15, 2005 at 17:43 UTC
Oh ok. That's even more evil than I would have normally thought. So &do_nothing; is like @_=do_nothing(@_) except that it doesn't make copies like would happen in that snippet.	[reply]