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Inheritance-like problem in Rust
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/// Problem: there is a lot of duplication in function implementations. | |
/// The two types should have the same interface but use a different underlying type. | |
/// | |
/// How can I reduce the amount of duplication and avoid having to update the code in two places? | |
/// In other languages, I would define a base class which accepts a generic type for the `SoundSource`s | |
/// but I don't know how to solve this sort of problem in Rust. | |
struct Sound { | |
// Shared properties | |
is_playing: bool, | |
// Sort of shared | |
source: SoundSource, | |
} | |
struct SpatialSound { | |
// Shared properties | |
is_playing: bool, | |
// Sort of shared (is a superset of SoundSource in terms of interface) | |
source: SpatialSoundSource, | |
} | |
impl Sound { | |
fn play(&mut self) { | |
self.stop(); | |
self.play_later(); | |
} | |
fn stop(&mut self) { | |
self.source = SoundSource::new(); | |
self.is_playing = false; | |
} | |
fn play_later(&mut self) { | |
self.source.play_later(); | |
self.is_playing = true; | |
} | |
} | |
impl SpatialSound { | |
// Duplicate of Sound::play | |
fn play(&mut self) { | |
self.stop(); | |
self.play_later(); | |
} | |
// Duplicate of Sound::stop but with a different type | |
fn stop(&mut self) { | |
self.source = SpatialSoundSource::new(); | |
self.is_playing = false; | |
} | |
// Mostly duplicate of Sound::play_later | |
fn play_later(&mut self) { | |
self.source.reset_position(); // Here's how it differs | |
self.source.play_later(); | |
self.is_playing = true; | |
} | |
} |
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