Rust 特征与类型的界限

Question

我正在阅读 hyperium/http source code and I found this:

pub fn put<T>(uri: T) -> Builder
 where
    Uri: TryFrom<T>,
    <Uri as TryFrom<T>>::Error: Into<crate::Error>,

{
    Builder::new().method(Method::PUT).uri(uri)
}

在此代码段中，Uri 是一种类型，T 是一种通用元素。我一直看到 where T: SomeTrait 的结构，但没有看到 SomeType: SomeTrait<T>。这个结构有名字吗？在某处有记录吗？

Answer 1

引用 https://doc.rust-lang.org/reference/trait-bounds.html#higher-ranked-trait-bounds:

Bounds on an item must be satisfied when using the item. When type checking and borrow checking a generic item, the bounds can be used to determine that a trait is implemented for a type. For example, given Ty: Trait

In the body of a generic function, methods from Trait can be called on Ty values. Likewise associated constants on the Trait can be used. Associated types from Trait can be used. Generic functions and types with a T: Trait bounds can be used with Ty being used for T.

没有任何内容表明 Ty 是类型参数（而不是固定类型）。所以我想说这只是一个特征限制，尽管不可否认在 Rust 教程中并不经常遇到。

Rust 特征与类型的界限

Rust trait bounds with types

generics

traits

rust