▁is ▁the ▁native ▁exception ▁handling ▁mechanism ▁for ▁Windows ▁and ▁a ▁for er un ner ▁technology ▁to ▁Vector ed ▁Exception ▁Hand ling ▁( VE H ). ▁It ▁features ▁the ▁finally ▁mechanism ▁not ▁present ▁in ▁standard ▁C ++ ▁exceptions ▁( but ▁present ▁in ▁most ▁imper ative ▁languages ▁introduced ▁later ). ▁SE H ▁is ▁set ▁up ▁and ▁handled ▁separately ▁for ▁each ▁thread ▁of ▁execution . ▁ ▁Us age ▁▁ ▁Microsoft ▁supports ▁SE H ▁as ▁a ▁programming ▁technique ▁at ▁the ▁compiler ▁level ▁only . ▁MS ▁Visual ▁C ++ ▁compiler ▁features ▁three ▁non - standard ▁keywords : ▁__ try , ▁__ except ▁and ▁__ fin ally ▁— ▁for ▁this ▁purpose . ▁Other ▁exception ▁handling ▁aspects ▁are ▁back ed ▁by ▁a ▁number ▁of ▁Win 3 2 ▁API ▁functions , ▁for ▁example , ▁Ra ise Exception ▁to ▁raise ▁SE H ▁exceptions ▁manually . ▁ ▁Im plementation ▁ ▁I A - 3 2 ▁ ▁Each ▁thread ▁of ▁execution ▁in ▁Windows ▁I A - 3 2 ▁edition ▁or ▁the ▁Wo W 6 4 ▁em ulation ▁layer ▁for ▁the ▁x 8 6 - 6 4 ▁version ▁has ▁a ▁link ▁to ▁an ▁und ocument ed ▁_ EX CE PT ION _ REG IST R ATION _ RE C ORD ▁list ▁at ▁the ▁start ▁of ▁its ▁Thread ▁Information ▁Block . ▁The ▁__ try ▁statement ▁essentially ▁calls ▁a ▁compiler - defined ▁E H _ pro log ▁function . ▁That ▁function ▁alloc ates ▁an ▁_ EX CE PT ION _ REG IST R ATION _ RE C ORD ▁on ▁the ▁stack ▁pointing ▁to ▁the ▁__ except _