3 releases
0.1.2 | Dec 11, 2022 |
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0.1.1 | Dec 11, 2022 |
0.1.0 | Dec 10, 2022 |
#10 in #exposing
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Used in 5 crates
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5KB
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hidden-trait
This library is a proc macro to expose a trait implementation.
The case we are trying to solve here: a library exposes some concrete structure for people to use. There can be multiple of them (e.g. Vector2
, Vector3
, Vector4
in a math library), or maybe it's one per platform (Vulkan vs Metal). Important part is - internally the library would like to have a trait implemented by this public type, but it doesn't want to expose the trait itself because of ergonomic reasons. Hence, "hidden-trait" to rescue.
mod hidden {
trait Foo {
fn foo(&self) -> u32;
}
pub struct Bar;
#[hidden_trait::expose]
impl Foo for Bar {
fn foo(&self) -> u32 {
42
}
}
}
fn main() {
let bar = hidden::Bar;
// calling the trait method as if it's ours
bar.foo();
}
Dependencies
~1.5MB
~36K SLoC