1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
// Copyright 2019 LEXUGE // // This program is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program. If not, see <http://www.gnu.org/licenses/>. //! A type that ensures calculation safety and prevents itself from overflow //! # Get started //! //! ``` //! use scalc::SCell; //! //! fn main() -> Result<(), String> { //! let a = SCell::<i32>::new(12) * SCell::<i32>::new(3); //! assert_eq!(*a.ok_or("overflow")?.get_data(), 36); //! //! // Addition will result in `None` in the presence of overflow behavior(s) //! let a = SCell::<i32>::new(std::i32::MAX) + SCell::<i32>::new(1); //! assert_eq!(a.is_none(), true); //! Ok(()) //! } //! ``` //! //! You can also use [*New Type Idiom*](https://doc.rust-lang.org/stable/rust-by-example/generics/new_types.html) in combination of [`derive_more`](https://github.com/JelteF/derive_more) to have better experience. #![deny(missing_docs)] #[macro_use] mod macros; mod impls; /// The structure which ensures the calculation safety #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)] pub struct SCell<T> { data: T, } #[cfg(test)] mod tests { use super::SCell; #[test] fn overflow_add() { let a = SCell::<i32>::new(std::i32::MAX) + SCell::<i32>::new(1); assert_eq!(a.is_none(), true); } #[test] fn overflow_sub() { let a = SCell::<i32>::new(std::i32::MIN) - SCell::<i32>::new(1); assert_eq!(a.is_none(), true); } #[test] fn overflow_mul() { let a = SCell::<i32>::new(std::i32::MAX) * SCell::<i32>::new(2); assert_eq!(a.is_none(), true); } #[test] fn overflow_div() { let a = SCell::<i32>::new(std::i32::MIN) / SCell::<i32>::new(-1); assert_eq!(a.is_none(), true); } #[test] fn overflow_abs() { let a = SCell::<i32>::new(std::i32::MIN).abs(); assert_eq!(a.is_none(), true); } }