Std.Env.option

fn

This is a callable function.

What it does

The value given after a named argument, or None.

--out file and --out=file are both read, because both are written.

Read the signature

• The text after the name is the type checked by Pudu.
• Read arrows from left to right: inputs come first, and the final type is returned.
• Names inside [ ] are type arguments, such as the item type held by a collection.
• Option holds Some(value) or None when no value is available.