Macro checked_expr::checked_expr

checked_expr!() { /* proc-macro */ }

Procedural macro to convert normal integer operations into overflow-checked operations. The expression will evaluate to Some(result) if all operations succed or to None if any of the operations fails.

Examples

use checked_expr::checked_expr;
assert_eq!(checked_expr!(254_u8 + 1), Some(255));
assert_eq!(checked_expr!(255_u8 + 1), None);

// this even works on negation
assert_eq!(checked_expr!(-(-127 as i8)), Some(127));
assert_eq!(checked_expr!(-(-128 as i8)), None);

// you can also arbitrarily nest expressions although you sometimes need to be very
// explicit with the types on literals on the left hand side of operations
assert_eq!(checked_expr!((10_i32 - 8) * (40_i32 + 13) / 8), Some(13));