Mark AudioDecoderOptions as #[non_exhaustive]

[caass]

I saw in symphonia-play that clippy::needless_update is allowed because the fields of AudioDecoderOptions may change, but that shouldn't require a code change to symphonia-play. The intended mechanism for this is to use the #[non_exhaustive] marker on AudioDecoderOptions, but that requires more code since non_exhaustive structs can't be updated with a spread pattern.

The "right" way to do this would be to create some sort of builder, either by hand or with something like bon, so that downstream users would call AudioDecoderOptions::builder().verify(bool).build(). i.e.:

// symphonia-core/src/codecs/audio.rs

use bon::Builder;

/// `AudioDecoderOptions` is a common set of options that all audio decoders use.
#[derive(Copy, Clone, Debug, Default, Builder)]
#[non_exhaustive]
pub struct AudioDecoderOptions {
    /// The decoded audio should be verified if possible during the decode process.
    #[builder(default)]
    pub verify: bool,
}

[caass]

This same lint exists in symphonia-check for DecoderOptions and FormatOptions

[pdeljanov]

Thanks for the report.

There are a few other cases which I've been hesitating tagging with #[non_exhaustive] for similar reasons. This will need to be fixed for 0.6 of course. Bon looks really great, though, so far I've preferred to roll my own builders to keep things simple and keep the build times as short as possible.

Tagging with the 0.6 milestone to make sure this gets fixed.