Share Calculation

Financial calculations in SplitPay must never panic or silently overflow. All mathematical operations use Rust's checked methods.

Checked Integer Arithmetic

Every multiplication, division, addition, and subtraction in the contract is checked:

• checked_mul() prevents multiplication overflow when multiplying large payments by BPS.
• checked_div() handles integer division by 10,000.
• checked_add() and checked_sub() prevent underflow and overflow.

Overflow & Truncation Protection

Any arithmetic failure results in Error::ArithmeticOverflow (17), aborting the transaction before any token transfer can occur.

Mathematical Invariant Formula