Crate protean 

protean

A flexible data type with serde support (serde feature).

Why?

I found myself making a similar data type quite often for serialized communication of flexible values.

Note: A lot of serialization formats are not “self-describing” and commonly use integer discriminants for enum variants. This crate will make sure to never reorder variants.

Example

use protean::DataCell;

let float_number = DataCell::f32(255.0);
let as_int = float_number.try_as_u8().expect("Float as number...");
assert_eq!(as_int, 255u8);

// Floats above ~16.7 million cannot be safely
// represented as an int, which we catch.
let high_float_number = DataCell::f32(17_000_000.0);
assert_eq!(high_float_number.try_as_u32(), None);
// ... but it does work for f64:
let high_float_number = DataCell::f64(17_000_000.0);
assert_eq!(high_float_number.try_as_u32(), Some(17_000_000));

// Integers can also be safely converted to floats
// if they fit without precision loss.
let int_number = DataCell::u32(2_930);
assert_eq!(int_number.try_as_f32(), Some(2_930.0));

// Again, precision starts to fall off around 16.7 million:
let high_int_number = DataCell::u32(17_000_000);
assert_eq!(high_int_number.try_as_f32(), None);
// ... but works for f64:
assert_eq!(high_int_number.try_as_f64(), Some(17_000_000.0));

Enums

DataCell

A flexible, fundamental unit of data.