3); return 会立即从函数返回 (是一个提前返回):use std::fs::File; use std::io::{Error, ErrorKind, Read, Result}; fn main() -> Result<()> { let mut file = match File::open("foo.txt") { Ok(f) => f, Err(e) => return Err(e), }; let mut contents = String::new();...
等需要返回结果的时候，调用Task的Result属性，若此时异步代码已经执行完，便可以立马拿到返回结果，若还没...
return 只能由直接 caller 处理，在 TypeScript 里声名返回类型可以是 Error，你是强迫直接 caller 处理...
We define to_s to lazily convert the raw string to a Ruby string using the UTF-8 encoding and memoize the result. Any string generated by Rust will be valid UTF-8. Python #!/usr/bin/env python3 import sys, ctypes from ctypes import c_void_p, c_uint8 prefix = {'win32': ''}....
` operator can only be used in an async function that returns `Result` or `Option` (or another type that implements `FromResidual`) #9 319.5 --> src/main.rs:51:126 #9 319.5 50 | async fn index(Form(login): Form<Login>)-> Response<String>{ #9 319.5 | ___- #9 319.5 51...
Would it be better to define sub_width_opt, and really all the *_opt functions in terms of their Result<T, MaxWidthError> versions? pub(crate) fn sub_width_opt(&self, n: usize) -> Option<Shape> { self.sub_width(n, rustc_span::DUMMY_SP).ok() } Contributor Author camsteffen No...
public static int getLength(String str) { return str.length(); } String str = "Hello World"; int result = getLength(str); System.out.println(result); // 输出11 5. 在PHP中,return语句可以用于返回一个函数的结果,并结束函数的执行。例如,我们可以定义一个函数来计算两个数的乘积,并使用return语...
pub fn from_script(script: &script::Script, network: Network) -> Result<Address, Error> { if script.is_witness_program() { if script.witness_version() == Some(WitnessVersion::V0) && !(script.is_v0_p2wpkh() || script.is_v0_p2wsh()) { ...
From: https://rust-unofficial.github.io/patterns/idioms/return-consumed-arg-on-error.html For better performance, the argument is usually moved into function. Take the example ofString::from_utf8(): pub fn from_utf8(vec: Vec<u8>) -> Result<String, SomeError> ...
You can map each &str to String an collect the result using Vec::from_iter: use std::iter::FromIterator; let res = Vec::from_iter(my_string.split("something").map(String::from)); This question is the opposite of this one. Note that collect is implemented in terms of from_iter....