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//! Generic numeric types. //! //! This module contains types and traits to manipulate numeric types in a generic manner. For //! instance, in the standard library, the `f32` and `f64` trait share a lot of methods of the //! same name and same semantics. Still, it is not possible to use them generically. This module //! provides the [`FloatingPoint`] trait, implemented by both of those type, to remedy the //! situation. //! //! # Note //! //! The current implementation of those traits does not strive to be general, in the sense that //! not all the common methods of the same kind of types are exposed. Only were included the ones //! that are used in the rest of the library. pub use float::*; pub use signed::*; pub use unsigned::*; mod float; mod signed; mod unsigned; /// A trait implemented by any generic numeric type suitable for computations. pub trait Numeric: Sized + Copy + PartialEq + PartialOrd { /// This size of the type in bits. const BITS: usize; /// The null element of the type. const ZERO: Self; /// The identity element of the type. const ONE: Self; /// A value of two. const TWO: Self; /// The largest value that can be encoded by the type. const MAX: Self; } /// A trait that allows to generically cast one type from another. /// /// This type is similar to the [`std::convert::From`] trait, but the conversion between the two /// types is deferred to the individual `as` casting. If in doubt about the semantics of such a /// casting, refer to /// [the rust reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#type-cast-expressions). pub trait CastFrom<Input> { fn cast_from(input: Input) -> Self; } /// A trait that allows to generically cast one type into another. /// /// This type is similar to the [`std::convert::Into`] trait, but the conversion between the two /// types is deferred to the individual `as` casting. If in doubt about the semantics of such a /// casting, refer to /// [the rust reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#type-cast-expressions). pub trait CastInto<Output> { fn cast_into(self) -> Output; } impl<Input, Output> CastInto<Output> for Input where Output: CastFrom<Input>, { fn cast_into(self) -> Output { Output::cast_from(self) } } macro_rules! implement_cast { ($Input:ty, {$($Output:ty),*}) => { $( impl CastFrom<$Input> for $Output { fn cast_from(input: $Input) -> $Output { input as $Output } } )* }; ($Input: ty) => { implement_cast!($Input, {f32, f64, usize, u8, u16, u32, u64, u128, isize, i8, i16, i32, i64, i128}); }; ($($Input: ty),*) => { $( implement_cast!($Input); )* } } implement_cast!(f32, f64, u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, usize, isize); impl<Num> CastFrom<bool> for Num where Num: Numeric, { fn cast_from(input: bool) -> Num { if input { Num::ONE } else { Num::ZERO } } }