Function SubWithOverflow

postgres/parser/utils/arith.go:61–69

SubWithOverflow returns a-b. If ok is false, a-b overflowed.

(a, b int64)

// SubWithOverflow returns a-b. If ok is false, a-b overflowed.
func SubWithOverflow(a, b int64) (r int64, ok bool) {
	if b < 0 && a > math.MaxInt64+b {
		return 0, false
	}
	if b > 0 && a < math.MinInt64+b {
		return 0, false
	}
	return a - b, true
}

// Sub32to64WithOverflow returns a-b. If ok is false, b was outside the
// int32 range or a-b overflowed.