Target argument for `scale`, `map` etc?

[kchanqvq]

Is there a way to destructively output to a different tensor rather than the input tensor? scale! or map! doesn't seem to be capable of this.

[stylewarning]

Currently no, but it would be a welcome addition, since this is sometimes needed for efficiency.

[YarinHeffes]

We have map-to but we do not have a scale-to.

magicl/src/high-level/abstract-tensor.lisp

Lines 99 to 107 in 6b49aee

	(defgeneric map-to (function source target)
	(:documentation "Map elements of SOURCE by replacing the corresponding element of TARGET the output of FUNCTION on the source element")
	(:method ((function function) (source abstract-tensor) (target abstract-tensor))
	(policy-cond:with-expectations (> speed safety)
	((assertion (equalp (shape source) (shape target))))
	(map-indexes
	(shape source)
	(lambda (&rest dims)
	(apply #'(setf tref) (funcall function (apply #'tref source dims)) target dims))))))