Function si_number 

pub fn si_number<T>(s: &str) -> Result<T, String>
where
    <T as TryFrom<u128>>::Error: Display,
    <T as FromStr>::Err: Display,
    T: CheckedAdd + CheckedMul + CheckedSub + FromStr + PartialOrd + TryFrom<u128> + Zero,

Validate a signed or unsigned integer value with a metric prefix.

This can accept strings with the (case sensitive) SI symbols.

Symbol	Name	Value
Y	yotta	1_000_000_000_000_000_000_000_000
Z	zetta	1_000_000_000_000_000_000_000
E	exa	1_000_000_000_000_000_000
P	peta	1_000_000_000_000_000
T	tera	1_000_000_000_000
G	giga	1_000_000_000
M	mega	1_000_000
k	kilo	1_000

The strings can be provided with a decimal, or using the SI symbol as the decimal separator.

String	Value
3k3	3300
3.3k	3300
1M	1_000_000

Example

This allows for resistance value to be passed using SI symbols.

use clap::Parser;
use clap_num::si_number;

#[derive(Parser)]
struct Args {
    #[clap(short, long, value_parser=si_number::<u128>)]
    resistance: u128,
}

To run this example use cargo run --example resistance, giving arguments to the program after --, for example:

$ cargo run --example resistance -- --resistance 1M1
Resistance: 1100000 ohms