Determine if a string is numeric: Difference between revisions

<syntaxhighlight lang="rust">

// This function is not limited to just numeric types but rather anything that implements the FromStr trait.

}

</syntaxhighlight>

Sample code:

<syntaxhighlight lang="rust">

use std::str::FromStr;

fn parsable<T: FromStr>(s: &str) -> bool {

s.parse::<T>().is_ok()

}

fn main() {

let test_cases = [

"142857",

"3.14",

"not of this earth!"

];

let types: &[(&str, fn(&str) -> bool)] = &[

("i32", parsable::<i32> as fn(&str) -> bool),

("i64", parsable::<i32> as fn(&str) -> bool),

("i128", parsable::<i32> as fn(&str) -> bool),

("f64", parsable::<f64> as fn(&str) -> bool),

];

println!("");

for &case in &test_cases {

for &(type_name, parse_fn) in types {

println!(

"'{}' {} be parsed as {}",

case,

if parse_fn(case) { "can" } else { "_cannot_" },

type_name

);

}

println!("");

}

}

</syntaxhighlight>