The new stable version of @rustlang, Rust 1.52, was released just now! π¦π
This release contains quite a few new small but significant features.
A thread.
1/10
blog.rust-lang.org/2021/05/06/Rusβ¦
This release contains quite a few new small but significant features.
A thread.
1/10
blog.rust-lang.org/2021/05/06/Rusβ¦
My favourite new addition is `str::split_once`.
We already had str::split and str::splitn, which result in an iterator. But when parsing something simple, you often want to split something exactly once. For example, to parse a string containing `key=value`.
2/10
We already had str::split and str::splitn, which result in an iterator. But when parsing something simple, you often want to split something exactly once. For example, to parse a string containing `key=value`.
2/10
Another one I'm excited about is one of the first features I worked on: std::fmt::Arguments::as_str()
fmt::Arguments is returned by format_args!(), and appears in macros that support formatting.
as_str() allows handling the literal case without special-casing your macro:
3/10
fmt::Arguments is returned by format_args!(), and appears in macros that support formatting.
as_str() allows handling the literal case without special-casing your macro:
3/10
Next: #[deny(unsafe_op_in_unsafe_fn)]
This forces you to write `unsafe` to call unsafe functions, even when inside an unsafe fn. Most unsafe functions have a mostly (or fully) safe implementation, so separating 'unsafe to call' from 'unsafe implementation' is often useful.
4/10
This forces you to write `unsafe` to call unsafe functions, even when inside an unsafe fn. Most unsafe functions have a mostly (or fully) safe implementation, so separating 'unsafe to call' from 'unsafe implementation' is often useful.
4/10
![#![deny(unsafe_op_in_unsafe_fn)] pub unsafe fn dangerous()](https://pbs.twimg.com/media/E0uCDJ_XEAU2O4l.jpg)
The casting operator (`as`) already allowed converting from a reference to an array to a pointer to the first element (from &[T; N] to *const T). Starting in Rust 1.52, this also works for the mutable case (from &mut [T; N] to *mut T):
5/10
5/10
![let mut array = [1, 2, 3]; let ptr = &mut array as *](https://pbs.twimg.com/media/E0uDPkhWYAIYsqQ.jpg)
Another important library feature: slice::partition_point.
This performs a binary search through a slice, given a (boolean) predicate.
With `<= x` or `< x` as the predicate, this is equivalent to the `upper_bound` and `lower_bound` algorithms of the C++ standard library.
6/10
This performs a binary search through a slice, given a (boolean) predicate.
With `<= x` or `< x` as the predicate, this is equivalent to the `upper_bound` and `lower_bound` algorithms of the C++ standard library.
6/10
If you like reference-counted errors, Rust 1.52 now implements the Error trait for all Arc<T> for which T itself implements Error:
7/10
7/10
As in most recent Rust releases, more functions are turned into `const fn`s to allow use in compile-time evaluated expressions.
This time it's the ascii upper-/lowercase functions, char::len_utf8 and len_utf16, and all the integer division/remainder functions:
8/10
This time it's the ascii upper-/lowercase functions, char::len_utf8 and len_utf16, and all the integer division/remainder functions:
8/10
The last new feature I want to highlight is a Rustdoc feature: Task lists.
With the same syntax that's supported by some other markdown variants (e.g. GitHub's), you can now add checked and unchecked checkboxes in your documentation:
9/10
With the same syntax that's supported by some other markdown variants (e.g. GitHub's), you can now add checked and unchecked checkboxes in your documentation:
9/10
And with that, I'm ending this thread. :)
There's a few more changes and additions, which you can find in the full release notes:
github.com/rust-lang/rustβ¦
10/10
There's a few more changes and additions, which you can find in the full release notes:
github.com/rust-lang/rustβ¦
10/10
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![let mut a = vec![1, 2, 3]; let mut x = 0; std::thread::scop](https://pbs.twimg.com/media/FZ43SBhacAM2APA.jpg)
