Complex sentence: This might look like a smart way to assign the return value of malloc to ptr and check if it is NULL in one step, but the malloc call and the assignment to ptr is a side effect of evaluating the expression that forms the assert condition.
Split into simpler sentences: This might look like a smart way to assign the return value of malloc to ptr and check if it is NULL in one step. But the malloc call and the assignment to ptr is a side effect of evaluating the expression that forms the assert condition.