rust - What is the idiomatic way to do something when an Option …
2022年1月26日 · As Lukas suggested, the map_or method can also be used. Note that arguments passed to map_or are eagerly evaluated, so if performance is critical, you might want to consider map_or_else as an alternative. Rust 1.70+ The is_some_and method has been stabilized in Rust 1.70. Here is an example:
rust - How to handle Result in flat_map - Stack Overflow
2020年1月22日 · I know we can use collect to move a Result from inner to outer, like: fn produce_result(my_struct: &;MyStruct) -> Result<MyStruct, Error>; let my_results: Vec<MyStruct> = vec![]...
rust - what is diference between map, and for_each to collect a ...
2023年1月18日 · map().collect() is more idiomatic for a couple of reasons. For one a simple for loop is recommended over the use of for_each by it's own documentation unless it makes the code possible or more readable.
rust - How do I create a HashMap literal? - Stack Overflow
2014年12月21日 · There isn't a map literal syntax in Rust. I don't know the exact reason, but I expect that the fact that there are multiple data structures that act maplike (such as both BTreeMap and HashMap) would make it hard to pick one. Rust 1.56. Many collections now offer conversions from an array argument using From or Into:
rust: static map initialization with enum keys - Stack Overflow
2024年3月1日 · First up: I am a very newbie with Rust; learning. This issue arises most probably from thinking in terms of other languages. So most probably the best solution is doing this in a completely different way. Things don't even compile yet, so apologies if the code has fundamental problems. I am defining my first trait.
rust - How can I update a value in a mutable HashMap ... - Stack …
2015年5月23日 · Not that you should do it, but as an exercise you can add Index and IndexMut to a custom hashmap type. use std::collections::HashMap; use std::ops::{Index, IndexMut ...
How do you call an async method within a closure (like within …
2021年7月12日 · I have the following: struct Foo { id: u32, } impl Foo { async fn get(id: u32) -> Result<Self, Box<;dyn Error>> { Ok(Self{ id }) } async fn something() { let ...
rust - Can match on Result here be replaced with map_err and ...
2020年1月11日 · Thanks! The return value isn't actually a string but an array of enum values, derived from the client, which is why I think I ended up with the lifetime parameter like that - this just got lost in trying to find a simple example with the same problem.
rust - What's the most idiomatic way of working with an Iterator of ...
2016年4月2日 · filter_map can be used to reduce simple cases of mapping then filtering. In your example there is some logic to the filter so I don't think it simplifies things.
rust - How to get the index of the current element being …
I have read How to iterate a Vec<T> with the indexed position? where the answer is to use enumerate in a for-loop.