Arithmetic Overflow & none Policies

Every arithmetic function family (math::add, math::sub, math::mul, math::div, math::rem) has explicit variants that decide what happens on overflow or missing input.

The policies

Variant	Behavior
math::add::none	Returns none on missing input or overflow.
math::add::saturate	Clamps to the type's minimum or maximum on overflow.
math::add::wrap	Wraps around on overflow (two's complement).
math::add::zero	Returns zero on missing input or overflow.
math::add::default	Returns the type's default value.
math::add::strict	Fails the statement on missing input or overflow.

Why explicit policies

Silent overflow and silently propagated missing values are the two classic numeric bugs. Naming the policy in the function makes the behavior visible in the query. This page will document each family with runnable examples per policy.