split-optional

It split from a source str to Option<&'a str> per an element.

Usage | Example

```rust fn main() { const SOME_INPUT: &str = "aaa,bbb,ccc";

// (Some("aaa"), Some("bbb,ccc")) let result = splitoptional::split2(SOMEINPUT, ","); println!("{result:?}");

// (Some("aaa"), Some("bbb"), Some("ccc")) let result = splitoptional::split3(SOMEINPUT, ","); println!("{result:?}");

// (Some("aaa"), Some("bbb"), Some("ccc"), None) let result = splitoptional::split4(SOMEINPUT, ","); println!("{result:?}");

// (Some("aaa"), Some("bbb"), Some("ccc"), None, None) let result = splitoptional::split5(SOMEINPUT, ","); println!("{result:?}"); } ```