short: Not faster. Sometimes actually slower.
long:
According to Stas Boukarev from SBCL-devel,
SBCL doesn't even know that a function has no side effects, so, no. Besides, most of the time having side effects is the most optimal way.
I am aware of the fact that functions such as nreverse
, which are destructive, tend to be faster than nondestructive functions (in this case reverse
is the nondestructive version). They also come with many setbacks. As Peter Siebel put it:
Each recycling function is a loaded gun pointed footward.