该程序之所以死是因为无限递归:
use std::any::Any;
trait Foo {
fn get(&self, index: usize) -> Option<&Any>;
}
impl Foo for Vec<i32> {
fn get(&self, index: usize) -> Option<&Any> {
Vec::get(self, index).map(|v| v as &Any)
}
}
fn main() {
let v: Vec<i32> = vec![1, 2, 4];
println!("Results: {:?}", v.get(0))
}
编译器本身对此发出警告:
warning: function cannot return without recurring
--> src/main.rs:8:5
|
8 | fn get(&self, index: usize) -> Option<&Any> {
| _____^ starting here...
9 | | Vec::get(self, index).map(|v| v as &Any)
10 | | }
| |_____^ ...ending here
|
= note: #[warn(unconditional_recursion)] on by default
note: recursive call site
--> src/main.rs:9:9
|
9 | Vec::get(self, index).map(|v| v as &Any)
| ^^^^^^^^^^^^^^^^^^^^^
= help: a `loop` may express intention better if this is on purpose
为什么在这种情况下通用调用语法不起作用?编译器不明白,我想打电话给Vec::get没有Foo::get。
如果我不想更改函数名称,该如何解决?