Add example showing how one can use owned options#594
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The `textwrap::Options<'a>` type is a little annoying: it insists on borrowing all its fields from somewhere else. In particular, the indentation fields are of type `&'a str`. This means that it’s not really possible for a program to store an `Options<'a>` and use it later if the fields are anything but string literals (of type `&str`). However, what does work is to create the `Options<'a>` on demand. Since all functions that need the options take an argument of type `impl Options<'a>`, you can easily convert your own type as needed. This can be as cheap as possible, i.e., converting `String` fields to `&str`. From the discussion in #592.
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The
textwrap::Options<'a>type is a little annoying: it insists on borrowing all its fields from somewhere else. In particular, the indentation fields are of type&'a str. This means that it’s not really possible for a program to store anOptions<'a>and use it later if the fields are anything but string literals (of type&str).However, what does work is to create the
Options<'a>on demand. Since all functions that need the options take an argument of typeimpl Options<'a>, you can easily convert your own type as needed. This can be as cheap as possible, i.e., convertingStringfields to&str.From the discussion in #592.