On 10/21/24 12:49 PM, Alice Ryhl wrote:
On 10/21/24 9:34 PM, John Hubbard wrote:
On 10/21/24 12:26 PM, Alice Ryhl wrote:
On Mon, Oct 21, 2024 at 9:09 PM John Hubbard <jhubbard@xxxxxxxxxx> wrote:
...
Rust macros can use different types of brackets. For example, the
`assert!(1 < 2)` macro uses round parenthesises, the `vec![1,2,3]`
macro uses square parenthesises, and the `thread_local! { ... }` macro
uses curly parenthesies. The round and square brackets are used for
expression-like things, and the curlies are used for things that
expand to top-level items such as global variables or functions.
Macros cannot use any other delimiter than those three. So e.g. <>
wouldn't work.
That answers my implicit "are there any cases in which you would
want to collectively refer to all three types of...bracket?", yes.
For the original point, though, we are not in a Rust macro. Is it
actually allowable to use [] or {} here:
+ // Brackets around PAGE_SIZE-1 to avoid triggering overflow sanitizers in the wrong cases.
+ (addr + (PAGE_SIZE - 1)) & PAGE_MASK
? Is that why you were not seeing a difference between saying "brackets"
vs. "parentheses" there? If so, this would be yet another case of my
Rust newbie-ness being inflicted on you. :)
You can use both () and {}, but you can only use brackets if you're European. ;)
I *knew* I was missing out! hahaha
Using {} to create a block works because a block evaluates to the value of the last expression in the block. It would be super weird to define a block here, though.
No argument there. :)
thanks,
--
John Hubbard
