Crate overflow_proof[−][src]
Expand description
Monadic checked arithmetic for Rust
This library provides types wrapping raw numeric types, and tracking possibility of an overflow, enforcing correct handling without possibility of panics or incorrect values (when overflow checks in release build are disabled).
Checked
is the main type provided by this library.
use overflow_proof::Checked;
let a = Checked::new(2u8);
let b = Checked::new(100u8);
// Aritmetic operations can be chained like with normal types
assert!({ ((a + 2) / 3 + 5) * b + 1}.check().is_none());
assert_eq!(*{ a + 2 + b }.check().expect("overflow"), 104);
use overflow_proof::{Checked, WithDeref};
struct OverflowError;
struct BankAccount {
balance: Checked<u64, >,
}
impl BankAccount {
fn debit(&mut self, amount: u64) -> Result<(), OverflowError> {
// Will not compile:
// Ok(self.balance -= amount)
// Overflow must be checked:
Ok(self.balance = {self.balance - amount}.check().ok_or(OverflowError)?)
}
}
Structs
A wrapper around a numeric type, containing a valid value, that will perform overflow checks on arithmetic operations.
Marker for Checked
that must be explicitly converted to the inner type.