使用Box<dyn Error>的代码如下: usestd::{error::Error,fs::read_to_string};fnmain()->Result<(),Box<dynError>>{lethtml=render_markdown()?;println!("{}",html);Ok(())}fnrender_markdown()->Result<String,Box<dynError>>{letfile=std::env::var("MARKDOWN")?;letsource=read_to_string(...
BufReader实现了std::io::BufRead这个trait,它提供了lines这个方法。 这个lines返回一个迭代器,迭代器的元素是Result<String, std::io::Error>类型的,它们来自request的stream,然后被切割成一项一项的。切割的过程自然是有可能出错的,比如需要转换成字符串,如果这个数据不符合utf-8的编码,那就会出问题了。 然后我...
This is an alias for a result type with a genericErrortype parameter and a unit (()) success type. Used to simplify the return types of functions that can either produce an error or succeed without returning a value. InvalidCodegenOptionstructure: A structure representing an invalid code gener...
和Option一样,Result类型也有一个在标准库中定义的unwrap方法,我们试试定义它: Copy // result-defimpl<T, E: ::std::fmt::Debug>Result<T, E> {fnunwrap(self)->T {matchself{ Result::Ok(val) => val, Result::Err(err) =>panic!("called `Result::unwrap()` on an `Err` value: {:?}"...
Error` can implement `error::Error`.implfmt::DisplayforCreationError{fnfmt(&self,f:&mutfmt::Formatter)->fmt::Result{letdescription=match*self{CreationError::Negative=>"number is negative",CreationError::Zero=>"number is zero",};f.write_str(description)}}implerror::ErrorforCreationError{}...
Instead of dealing with one error type (namely,CloudFileError), multiple error types are possible, so we fall back to using theanyhowcrate. Whether you useobject_store(with 2.4 million downloads) directly or indirectly viacloud-file(currently, with 124 downloads 😀),...
rustc_codegen_gcc是 Rust 编译器的一个后端,它负责将 Rust 代码编译为目标平台上的机器代码。simd.rs是其中的一个源代码文件,在该文件中定义了一些与 SIMD(Single Instruction, Multiple Data)相关的内置函数。 SIMD 是一种计算机处理器的特性,它允许同时对多个数据进行相同类型的并行计算。SIMD 指令集对于某些计算...
{ code: 2, kind: NotFound, message: "No such file or directory" } stack backtrace: 0: rust_begin_unwind 1: core::panicking::panic_fmt 2: core::result::unwrap_failed 3: rustc_errors::markdown::term::tests::test_output 4: <rustc_errors::markdown::term::tests::test_output::{...
(conn: &mut Conn, callback: F) -> Result<R, E> 51 | | where 52 | | F: FnOnce(&mut Conn) -> Result<R, E>, 53 | | E: From<Error>, | |___^ note: candidate #2 is defined in the trait `connection::Connection` --> diesel/src/connection/mod.rs:302:5 | 302 | / fn...
these types all implement a new`LendingIterator`trait. We define this ourselves because there is currently no widely-used crate that implements it. 并且修复commit中,作者提到 Make ResultIterator a LendingIterator 换句话说,将这些迭代器修改为LendingIterator,尤其是这个ResultIterator,就能解决问题。那么总结...