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   mcc (mcc@mastodon.social)'s status on Monday, 30-Dec-2024 06:29:44 JST mcc

   I wish there was an easier way in Rust to implement Default on a type by supplying an exemplar const value without having to like do the whole multiline impl fn dance

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     Cassandra Granade 🏳️‍⚧️ (xgranade@wandering.shop)'s status on Monday, 30-Dec-2024 06:29:44 JST Cassandra Granade 🏳️‍⚧️

     in reply to

     @mcc That seems like something that should be doable with a macro, honestly. Surprised no one has written it yet...

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     mcc (mcc@mastodon.social)'s status on Monday, 30-Dec-2024 06:33:38 JST mcc

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     • Cassandra Granade 🏳️‍⚧️

     @xgranade maybe someone has, crates.io is large

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     mcc (mcc@mastodon.social)'s status on Monday, 30-Dec-2024 06:33:38 JST mcc

     in reply to

     • Cassandra Granade 🏳️‍⚧️

     @xgranade rust has so much less copypaste than C but the places where the copypaste shows up are all surprising

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     Cassandra Granade 🏳️‍⚧️ (xgranade@wandering.shop)'s status on Monday, 30-Dec-2024 06:33:38 JST Cassandra Granade 🏳️‍⚧️

     in reply to

     @mcc There is an incoming feature, IIRC, for default field values in structs, that should reduce the copypaste, at least, but yeah. Seems like something that would have had a more ergonomic approach a while ago.

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     mcc (mcc@mastodon.social)'s status on Monday, 30-Dec-2024 06:36:38 JST mcc

     in reply to

     • Cassandra Granade 🏳️‍⚧️

     @xgranade default field values are not my preferred solution but it's something. does this trigger as part of derive(default) or what?

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     Cassandra Granade 🏳️‍⚧️ (xgranade@wandering.shop)'s status on Monday, 30-Dec-2024 06:36:38 JST Cassandra Granade 🏳️‍⚧️

     in reply to

     @mcc The language feature was approved with https://github.com/rust-lang/rfcs/pull/3681, and documents that yeah, #[derive(Default)] will work if every field has a default value or itself implements Default.

     From the RFC:

     ```
     #[derive(Default)]
     struct Pet {
     name: Option<String>, // impl Default for Pet will use Default::default() for name
     age: i128 = 42, // impl Default for Pet will use the literal 42 for age
     }
     ```

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     mcc (mcc@mastodon.social)'s status on Monday, 30-Dec-2024 06:51:30 JST mcc

     in reply to

     • Cassandra Granade 🏳️‍⚧️

     @xgranade ok. i think this doesn't piss me off the way C#/C++/Java do because there's no "default members AND a constructor" option.

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     Cassandra Granade 🏳️‍⚧️ (xgranade@wandering.shop)'s status on Monday, 30-Dec-2024 06:51:30 JST Cassandra Granade 🏳️‍⚧️

     in reply to

     @mcc It does seem in general as though the Rust RFC process has made it possible to learn from where other languages have made mistakes.