Make all methods of `std::net::Ipv4Addr` const #76142

CDirkx · 2020-08-31T03:17:11Z

Make the following methods of std::net::Ipv4Addr unstable const under the const_ipv4 feature:

octets
is_loopback
is_private
is_link_local
is_global (unstable)
is_shared (unstable)
is_ietf_protocol_assignment (unstable)
is_benchmarking (unstable)
is_reserved (unstable)
is_multicast
is_broadcast
is_documentation
to_ipv6_compatible
to_ipv6_mapped

This would make all methods of Ipv6Addr const.

Of these methods, is_global, is_broadcast, to_ipv6_compatible, and to_ipv6_mapped require a change in implementation.

Part of #76205

Constify the following methods of `std::net::Ipv4Addr`: - `octets` - `is_loopback` - `is_private` - `is_link_local` - `is_shared` - `is_ietf_protocol_assignment` - `is_benchmarking` - `is_multicast` - `is_documentation` Also insta-stabilizes these methods as const. Possible because of the stabilization of const integer arithmetic and control flow.

rust-highfive · 2020-08-31T03:17:14Z

r? @joshtriplett

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jyn514 · 2020-08-31T04:39:34Z

r? @ecstatic-morse

https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Upcoming.20const-stabilization.20PRs

ecstatic-morse · 2020-08-31T16:13:24Z

r? @KodrAus (Needs FCP)

jyn514 · 2020-08-31T16:39:16Z

Maybe these could be made rustc_const_unstable so that it's easy to change them all at once? And then have FCP to stabilize on individual methods?

CDirkx · 2020-08-31T16:56:46Z

That is also possible, I was going over all methods of IpAddr, Ipv4Addr and Ipv6Addr and seeing what needs to be done to make them const.

I will open a tracking issue soon to provide an overview, with that we could decide what the best path forward is.

ecstatic-morse · 2020-08-31T17:06:14Z

I think we should see if anyone on the libs team actually has an issue with these becoming const fn. If so, we can switch to rustc_const_unstable. Also, the implementation changes required for every Ip{,v4,v6}Addr are non-invasive and should be performance neutral. Mostly it's calls to concrete implementations of From::from, which can be worked around with either a separate const fn or the unstable (and only partially implemented) const_trait_impl feature. I wouldn't do this until the libs team weighs in though.

CDirkx · 2020-09-01T17:52:54Z

Opened #76205.

Made the methods unstable const under const_ipv4 for now.

CDirkx · 2020-09-01T20:24:38Z

Tests added. I was working on the followup PR with the methods that require a change in implentation to make const. However now that this PR no longer makes everything also stable, I think I'm just going to include those changes here.

Makes the following methods of `std::net::Ipv4Addr` unstable const under the `const_ipv4` feature: - `is_global` - `is_reserved` - `is_broadcast` - `to_ipv6_compatible` - `to_ipv6_mapped` This results in all methods of `Ipv4Addr` being const. Also adds tests for these methods in a const context.

CDirkx · 2020-09-01T22:08:51Z

library/std/src/net/ip.rs

        let [a, b, c, d] = self.octets();
-        Ipv6Addr::from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a, b, c, d])
+        Ipv6Addr {
+            inner: c::in6_addr { s6_addr: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a, b, c, d] },


Not the prettiest solution, using implementation details from Ipv6Addr. Considered adding a non-pub method from_octets to Ipv6Addr, but it seemed out of place.

CDirkx · 2020-09-01T22:10:09Z

Updated the title and PR description to accurately reflect that this now covers all methods of Ipv4Addr.

ecstatic-morse · 2020-09-02T18:02:36Z

LGTM! Someone pointed out to me on Zulip that we should be using unit tests in the standard library as opposed to UI tests for these, so let's do that in the future. They're a bit faster than a run-pass test.

@bors r+ rollup

bors · 2020-09-02T18:02:37Z

📌 Commit 0c77257 has been approved by ecstatic-morse

@ghost

Rollup of 12 pull requests Successful merges: - rust-lang#75150 (Add a note for Ipv4Addr::to_ipv6_compatible) - rust-lang#76120 (Add `[T; N]::as_[mut_]slice`) - rust-lang#76142 (Make all methods of `std::net::Ipv4Addr` const) - rust-lang#76164 (Link to slice pattern in array docs) - rust-lang#76167 (Replace MinGW library hack with heuristic controlling link mode) - rust-lang#76204 (Rename and expose LoopState as ControlFlow) - rust-lang#76238 (Move to intra-doc links for library/core/src/iter/traits/iterator.rs) - rust-lang#76242 (Read: adjust a FIXME reference) - rust-lang#76243 (Fix typos in vec try_reserve(_exact) docs) - rust-lang#76245 (inliner: Avoid query cycles when optimizing generators) - rust-lang#76255 (Update books) - rust-lang#76261 (Use intra-doc links in `core::marker`) Failed merges: r? @ghost

@ecstatic-morse

Make delegation methods of `std::net::IpAddr` unstably const Make the following methods of `std::net::IpAddr` unstable const under the `const_ip` feature: - `is_unspecified` - `is_loopback` - `is_global` - `is_multicast` Also adds a test for these methods in a const context. Possible because these methods delegate to the inner `Ipv4Addr` or `Ipv6Addr`, which were made const ([PR#76205](rust-lang#76142) and [PR#76206](rust-lang#76206)), and the recent stabilization of const control flow. Part of rust-lang#76205 r? @ecstatic-morse

rust-highfive assigned joshtriplett Aug 31, 2020

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 31, 2020

rust-highfive assigned ecstatic-morse and unassigned joshtriplett Aug 31, 2020

jyn514 added A-const-fn T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. labels Aug 31, 2020

rust-highfive assigned KodrAus and unassigned ecstatic-morse Aug 31, 2020

Make methods unstable const under const_ipv4

ee9e48b

CDirkx mentioned this pull request Sep 1, 2020

Constify std::net::IpAddr, Ipv4Addr, and Ipv6Addr #76205

Closed

Add test for Ipv4Addr methods in a const context

fb64e6d

CDirkx changed the title ~~Make more Ipv4Addr methods const~~ Make all methods of std::net::Ipv4Addr const Sep 1, 2020

CDirkx commented Sep 1, 2020

View reviewed changes

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 2, 2020

Dylan-DPC-zz mentioned this pull request Sep 3, 2020

Rollup of 12 pull requests #76265

Merged

bors merged commit 9605f94 into rust-lang:master Sep 3, 2020

CDirkx deleted the const-ip branch September 3, 2020 21:57

CDirkx mentioned this pull request Sep 3, 2020

Make delegation methods of std::net::IpAddr unstably const #76304

Merged

cuviper added this to the 1.48.0 milestone Nov 17, 2023

RalfJung added the A-const-eval Area: Constant evaluation, covers all const contexts (static, const fn, ...) label Dec 1, 2024

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Make all methods of `std::net::Ipv4Addr` const #76142

Make all methods of `std::net::Ipv4Addr` const #76142

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Make all methods of std::net::Ipv4Addr const #76142

Make all methods of std::net::Ipv4Addr const #76142

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Make all methods of `std::net::Ipv4Addr` const #76142

Make all methods of `std::net::Ipv4Addr` const #76142

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