fdec
A collection of macros for generating fixed-size fixed-point numeric types that exactly fit your domain. The types are fully equipped for performing mathematical computations and are easy to use.
With a simple macro call you get a type that:
- has no representation errors in the range, defined by the type parameters,
- supports arithmetic operations:
+
,-
,*
,/
,%
,<<
,>>
, - comes with mathematical functions:
abs()
,powi()
,sqrt()
, - has special values NaN and ±Infinity, and uses them instead of panicing,
- provides basic mathematical constants,
- seamlessly interacts with Rust's primitive types,
- converts values to/from byte arrays,
- creates values and performs math operations on stack, avoiding heap allocations.
When to Use
You should probably give fdec a try if:
- you need primitive types like
i256
ori1408
, which Rust doesn't provide, - your business domain is not tolerant to representation errors that may add up during computations (like working with money in finance),
- other libraries that provide decimal numbers are not fast enough for you when it comes to doing math,
- you need to store lots of decimal numbers, and you'd prefer it to be memory-efficient,
- you're just curious to see how it works.
How to Use
Add the dependency on fdec
to your Cargo.toml
:
[]
= "0.3.1"
Import it at your crate's root with the macro_use
attribute:
extern crate fdec;
Add custom numeric types to your project by calling fdec*
macros:
fdec64!
Example
Here we define the Decimal
structure that represents 160-bit numbers
with 30 decimal places.
extern crate fdec;
fdec32!
use *; // Bring the generated stuff to the scope
More examples come with the crate's source code:
- Many ways to create values: creation.rs
- Compute Fibonacci numbers: fibonacci.rs
- Calculate square root with high precision: sqrt.rs