use std::fs::read_to_string; #[derive(thiserror::Error, Debug)] enum MyCustomError { #[error("环境变量不存在")] EnvironmentVariableNotFound(#[from] std::env::VarError), #[error(transparent)] IOError(#[from] std::io::Error), } // 方法里可能会发生VarError或std::io::Error错误,...
In the former case the expect message is used to describe the error that has occurred which is considered a bug. Consider the following example: // Read environment variable, panic if it is not present let path = std::env::var("IMPORTANT_PATH").unwrap(); In the "expect as error messa...
;println!("{}", html);Ok(())}fn render() -> Result<String, MyError> {let file = std::env::var("MARKDOWN")?;let source = read_to_string(file)?;Ok(source)}#[derive(thiserror::Error, Debug)]enum MyError {#[error("Environment variable not found")]EnvironmentVariableNot...
// Read environment variable, panic if it is not present let path = std::env::var("IMPORTANT_PATH").unwrap(); In the "expect as error message" style we would use expect to describe that the environment variable was not set when it should have been: 代码语言:javascript 代码运行次数:...
thread'main'panicked at'error occured',src\main.rs:3:5note:runwith`RUST_BACKTRACE=1`environment variable to display a backtrace. 很显然,程序并不能如约运行到 println!("Hello, Rust") ,而是在 panic! 宏被调用时停止了运行。 不可恢复的错误一定会导致程序受到致命的打击而终止运行。
Please enter an array index.10thread'main'panicked at'index out of bounds: the len is 5 but the index is 10',src/main.rs:48:19note:runwith`RUST_BACKTRACE=1`environment variable to display a backtrace 程序在索引操作中使用一个无效的值时导致 运行时 错误。程序带着错误信息退出,并且没有执行...
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace error: process didn't exit successfully: `target\debug\cargo_learn.exe` (exit code: 101) panic!宏命令与js中的throw Error属于同一性质,所以相对于nodejs而言是同一个概念 ...
- lifetime: a variable's(变量) lifetime begins when it is created and ends when it is destroyed. - scope: the scope of the borrow is determined by where the reference is used. --- 在之前的例子中,我们看到,`thread::spawn`需要一个`'static`的闭包,但是为什么编译器会建议我们,将`&self`...
thread'main'panickedat'library/core/src/panicking.rs:220:5:unsafeprecondition(s)violated:slice::from_raw_partsrequiresthepointertobealignedandnon-null,andthetotalsizeoftheslicenottoexceed`isize::MAX`',note:runwith`RUST_BACKTRACE=1`environmentvariabletodisplayabacktrace ...
$cdRustPython $ cargo run --release demo_closures.py Hello, RustPython! Or use the interactive shell: $ cargo run --release Welcome to rustpython >>> 2+2 4 NOTE: For windows users, please setRUSTPYTHONPATHenvironment variable asLibpath in project directory. (e.g. When RustPython directo...