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53 lines
1.3 KiB
Markdown
53 lines
1.3 KiB
Markdown
# Multitrait Object [](https://crates.io/crates/multi-trait-object) [](https://docs.rs/multi-trait-object)
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This crate provides a pointer type that allows casting into
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all registered traits for a given type.
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This is done by storing the pointer to the v-table for each
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trait implementation on the type as well as the pointer to the
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data.
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## Safety
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All unsafe parts are perfectly safe as far as my understanding goes.
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As this crate is still in an early stage there might be some side effects that haven't
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been noticed yet.
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## Usage
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```rust
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use multi_trait_object::*;
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use std::fmt::Debug;
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#[derive(Debug)]
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struct MyStruct {
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a: u64,
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}
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trait MyTrait {}
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trait MyOtherTrait {}
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impl MyTrait for MyStruct{}
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impl MyOtherTrait for MyStruct {}
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impl_trait_object!(MyStruct, dyn MyTrait, dyn MyOtherTrait, dyn Debug);
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fn main() {
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let obj = MyStruct {
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a: 5
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};
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let mto = obj.into_multitrait();
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{
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let debug = mto.downcast_trait::<dyn Debug>().unwrap();
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println!("{:?}", debug);
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let my_trait = mto.downcast_trait::<dyn MyTrait>().unwrap();
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}
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let trait_box: Box<dyn MyTrait> = mto.downcast_trait_boxed::<dyn MyTrait>().unwrap();
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}
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```
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## License
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Apache-2.0 |