试了一下let _个 = 个泛(个);也可以,如果参数是自己let _个泛 = 个泛(个泛);,则报错: error[E0282]: type annotations needed --> src/main.rs:28:18 | 28 | let _个泛 = 个泛(个泛); | ^^^ cannot infer type of the type parameter `T` declared on the struct `个泛` | help: c...
error[E0282]:typeannotationsneeded-->src/main.rs:2:9|2|letguess="42".parse().expect("Not a number!");|^^^|||cannotinfertypefor`_`|considergiving`guess`atype 最上面我们说道,当编译器无法推断出变量的类型的时候就需要我们自己声明变量类型,这就说明 parse 这个函数返回类型不确定,那么 parse 返...
In fact, type inference for typeSinHashSet<T, S>has nothing to do with the type ofT. The issue is that there is no information in your program that allows the compiler to infer the type ofS. It is correct that adding a type parameter is sufficient to resolve the ambiguity:...
96 | let cache = Cache::new::<Demo>(); | ^^^ cannot infer type for type parameter `T` | = note: cannot satisfy `_: DeserializeOwned` 但是如果我尝试为Demo对象实现DeserializeOwned,编译器会抱怨实现冲突。 任何帮助都将不胜感激:) 有两个独立的泛型类型参数,示例中的完全限定语法是Cache::<Dem...
cannot infer type forConn AI检测代码解析 error[E0282]: type annotations needed --> user/src/lib.rs:29:31 | 29 | let count: usize = repos::add_login_info( conn, &new_login_info).expect("add login info error"); | ^^^ cannot infer type for `Conn`12345 1. 2. 3. 4. 5. ...
error[E0282]: type annotations needed --> src/main.rs:34:15 | 34 | match map[x][y] { | ^^^ cannot infer type | = note: type must be known at this point 以下是源码,删除了无关紧要的内容 use rand::prelude::*; #[derive(Debug, Clone, Copy)] enum Point { Landmine, Num(u8...
error[E0282]: type annotations neededfor`(Sender<T>, std::sync::mpsc::Receiver<T>)`--> src/main.rs:60:19 | 60 | let (tx,rx) =mpsc::channel();| --- ^^^ cannot infer typefortype parameter `T` declared on the function `channel`| | | consider givingthispattern...
error[E0282]: type annotations needed --> src/main.rs:2:9 | 2 | let guess = "42".parse().expect("Not a number!"); | ^^^ | | | cannot infer type for `_` | consider giving `guess` a type 你会看到其它数据类型的各种类型注解。 标量...
error[[E0282]](https://doc.rust-lang.org/nightly/error_codes/E0282.html): type annotations needed --> src/main.rs:11:9 | 11 | Ok(()) | ^^ cannot infer type of the type parameter `E` declared on the enum `Result` | help: consider specifying the generic arguments | 11 | Ok:...
12 | create_and_print(); | ^^^ cannot infer type of the type parameter `T` declared on the function `create_and_print` | = note: multiple `impl`s satisfying `_: From<i32>` found in the `core` crate: - impl From<i32> for AtomicI32; - impl From<i32> for f64; - impl From...