What is the test for "cruel and unusual punishment" under s. 12 of the Charter?

In applying the test for “cruel and unusual treatment or punishment”, sight should not be lost that rare will be the occasion of its application. Authority for this proposition comes from Steele v. Établissement Mountain, 1990 CanLII 50 (SCC), [1990] 2 S.C.R. 1385, where a prisoner’s lengthy incarceration stemming from an indeterminate sentence was held cruel and unusual punishment contrary to s. 12 of the Charter. Of immediate relevance to this appeal are the following words of Cory J., speaking for an unanimous Court in Steele, where, immediately after ruling that the inordinate length of the prisoner’s incarceration had long since become grossly disproportionate to the circumstances of that case, he wrote at p. 1417: It will only be on rare and unique occasions that a court will find a sentence so grossly disproportionate that it violates the provisions of s. 12 of the Charter. The test for determining whether a sentence is disproportionately long is very properly stringent and demanding. A lesser test would tend to trivialise the Charter.