The [fixed crate] provides fixed-point numbers. Currently it uses the [typenum crate] for the fractional bit count; it is planned to move to [const generics] when they are implemented by the Rust compiler.
The crate provides the following types:
FixedI8] is a signed eight-bit fixed-point number,FixedI16] is a signed 16-bit fixed-point number,FixedI32] is a signed 32-bit fixed-point number,FixedI64] is a signed 64-bit fixed-point number,FixedI128] is a signed 128-bit fixed-point number,FixedU8] is an unsigned eight-bit fixed-point number,FixedU16] is an unsigned 16-bit fixed-point number,FixedU32] is an unsigned 32-bit fixed-point number,FixedU64] is an unsigned 64-bit fixed-point number, andFixedU128] is an unsigned 128-bit fixed-point number.All fixed-point numbers can have Frac fractional bits, where Frac
can have any value from 0 up to and including the size of the number
in bits. When Frac is 0, the fixed-point number behaves like an
integer. When Frac is equal to the number of bits, the value of the
fixed-point number lies in the range −0.5 ≤ x < 0.5 for signed
fixed-point numbers, and in the range 0 ≤ x < 1 for unsigned
fixed-point numbers.
All lossless infallible conversions between fixed-point numbers and
numeric primitives are implemented. That is, you can use [From] or
[Into] for the conversions that always work without losing any bits.
types] is available with aliases for all supported
fixed-point numbers.From] and [Into].FixedI128] and [FixedU128].Details on other releases can be found in [RELEASES.md].
```rust // 20 integer bits, 12 fractional bits use fixed::types::I20F12;
// 19/3 = 6 1/3 let sixandthird = I20F12::fromint(19).unwrap() / 3; // four decimal digits for 12 binary digits asserteq!(sixandthird.tostring(), "6.3333"); // convert to i32, taking the ceil asserteq!(sixandthird.tointceil(), 7); ```
The type [I20F12] is a 32-bit fixed-point signed number with 20
integer bits and 12 fractional bits. It is an alias to
[FixedI32<frac::U12>][FixedI32]. The unsigned counterpart would be
[U20F12]. Aliases are provided for all combinations of integer and
fractional bits adding up to a total of eight, 16, 32, 64 or 128 bits.
The fixed crate is available on crates.io. To use it in your crate, add it as a dependency inside [Cargo.toml]:
toml
[dependencies]
fixed = "0.1.5"
If you are using the 2015 Rust edition, you also need to declare it by adding this to your crate root (usually lib.rs or main.rs):
rust
extern crate fixed;
The fixed crate requires rustc version 1.28.0 or later.
The fixed crate has one optional feature:
f16, disabled by default. This provides conversion to/from
[f16]. This features requires the [half crate].To enable the feature, you can add the dependency like this to [Cargo.toml]:
toml
[dependencies.fixed]
version = "0.1.5"
features = ["f16"]
This crate is free software: you can redistribute it and/or modify it under the terms of either
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache License, Version 2.0, shall be dual licensed as above, without any additional terms or conditions.