Add missing Wrapping methods, use doc_comment!

[clarfonthey]

Part of #32463.

[rust-highfive]

r? @kennytm

(rust_highfive has picked a reviewer for you, use r? to override)

[kennytm]

r? @SimonSapin

[TimNN]

Your PR failed on Travis. Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

Resolving deltas: 100% (612388/612388), completed with 4838 local objects.
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[00:00:44] configure: rust.quiet-tests     := True
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[01:11:16] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "test" "--target" "x86_64-unknown-linux-gnu" "--release" "--locked" "--color" "always" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/checkout/src/libstd/Cargo.toml" "-p" "core" "--" "--quiet"
[01:11:16] expected success, got: exit code: 101
[01:11:16]
[01:11:16]
[01:11:16] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:11:16] Build completed unsuccessfully in 0:33:48
[01:11:16] Makefile:58: recipe for target 'check' failed
[01:11:16] make: *** [check] Error 1

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN.

[kennytm]

The actual error is doc-tests in core. Basically missing imports.

[01:11:16] ---- num/wrapping.rs - num::wrapping::Wrapping<u128>::is_power_of_two (line 684) stdout ----
[01:11:16] 	error[E0425]: cannot find function `Wrapping` in this scope
[01:11:16]  --> num/wrapping.rs:685:9
[01:11:16]   |
[01:11:16] 4 | assert!(Wrapping(16).is_power_of_two());
[01:11:16]   |         ^^^^^^^^ not found in this scope
[01:11:16] help: possible candidate is found in another module, you can import it into scope
[01:11:16]   |
[01:11:16] 3 | use std::num::Wrapping;
[01:11:16]   |
...

[clarfonthey]

Will fix that later today. Also was thinking of revamping the Wrapping docs to use doc_comment!, so, I'll do that also.

[scottmcm]

Sorry for giving you a bad commit; I sent a PR for the fix this morning: clarfonthey#2

[TimNN]

Your PR failed on Travis. Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

Resolving deltas: 100% (609943/609943), completed with 4836 local objects.
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[00:00:44] configure: rust.quiet-tests     := True
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---
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:689:9
[01:46:52]   |
[01:46:52] 8 | assert!(Wrapping(16).is_power_of_two());
[01:46:52]   |         ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:690:10
[01:46:52]   |
[01:46:52] 9 | assert!(!Wrapping(10).is_power_of_two());
[01:46:52]   |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:691:10
[01:46:52]    |
[01:46:52] 10 | assert!(!Wrapping(0).is_power_of_two());
[01:46:52]    |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52] note: Run with `RUST_BACKTRACE=1` for a backtrace.
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u128>::next_power_of_two (line 707) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:710:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_apping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:50
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |                                                  ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u16>::is_power_of_two (line 684) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:687:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:689:9
[01:46:52]   |
[01:46:52] 8 | assert!(Wrapping(16).is_power_of_two());
[01:46:52]   |         ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:690:10
[01:46:52]   |
[01:46:52] 9 | assert!(!Wrapping(10).is_power_of_two());
[01:46:52]   |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:691:10
[01:46:52]    |
[01:46:52] 10 | assert!(!Wrapping(0).is_power_of_two());
[01:46:52]    |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u16>::next_power_of_two (line 707) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:710:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:12
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:45
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:12
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]    |
[01:46:52] 5  | use std::num::Wrapping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:50
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |                                                  ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u32>::is_power_of_two (line 684) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:687:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:689:9
[01:46:52]   |
[01:46:52] 8 | assert!(Wrapping(16).is_power_of_two());
[01:46:52]   |         ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:690:10
[01:46:52]   |
[01:46:52] 9 | assert!(!Wrapping(10).is_power_of_two());
[01:46:52]   |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:691:10
[01:46:52]    |
[01:46:52] 10 | assert!(!Wrapping(0).is_power_of_two());
[01:46:52]    |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u32>::next_power_of_two (line 707) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:710:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:12
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:45
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:12
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]    |
[01:46:52] 5  | use std::num::Wrapping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:50
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |                                                  ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u64>::is_power_of_two (line 684) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:687:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:689:9
[01:46:52]   |
[01:46:52] 8 | assert!(Wrapping(16).is_power_of_two());
[01:46:52]   |         ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:690:10
[01:46:52]   |
[01:46:52] 9 | assert!(!Wrapping(10).is_power_of_two());
[01:46:52]   |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:691:10
[01:46:52]    |
[01:46:52] 10 | assert!(!Wrapping(0).is_power_of_two());
[01:46:52]    |          ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u64>::next_power_of_two (line 707) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:710:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:12
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:45
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:12
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]    |
[01:46:52] 5  | use std::num::Wrapping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:50
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |                                                  ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<u8>::is_power_of_two (line 684) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:687:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:689:9
[01:46:52]   |
[01:46:52] 8 | assert!(Wrapping(16).is_power_of_two());
[01:46:52]   |         ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:690:10
[01:46:52]   |
[01:46:52] 9 | assert!(!Wrapping(10).is_power_of_nction `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:12
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:45
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:12
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]    |
[01:46:52] 5  | use std::num::Wrapping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:50
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |                                                  ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46rror: unused import: `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:687:5
---
[01:46:52]   = note: #[deny(unused_imports)] implied by #[deny(warnings)]
[01:46:52]
[01:46:52] thread 'rustc' panicked at 'couldn't compile the test', librustdoc/test.rs:306:13
[01:46:52]
[01:46:52] ---- num/wrapping.rs - num::wrapping::Wrapping<usize>::next_power_of_two (line 707) stdout ----
[01:46:52]  error[E0432]: unresolved import `std::num::wrapping`
[01:46:52]  --> num/wrapping.rs:710:5
[01:46:52]   |
[01:46:52] 6 | use std::num::wrapping;
[01:46:52]   |     ^^^^^^^^^^^^^^^^^^ no `wrapping` in `num`. Did you mean to use `Wrapping`?
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:12
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:712:45
[01:46:52]   |
[01:46:52] 8 | assert_eq!(Wrapping(2).next_power_of_two(), Wrapping(2));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:12
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]  --> num/wrapping.rs:713:45
[01:46:52]   |
[01:46:52] 9 | assert_eq!(Wrapping(3).next_power_of_two(), Wrapping(4));
[01:46:52]   |                                             ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]   |
[01:46:52] 5 | use std::num::Wrapping;
[01:46:52]   |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/wrapping.rs:714:12
[01:46:52]    |
[01:46:52] 10 | assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));
[01:46:52]    |            ^^^^^^^^ not found in this scope
[01:46:52] help: possible candidate is found in another module, you can import it into scope
[01:46:52]    |
[01:46:52] 5  | use std::num::Wrapping;
[01:46:52]    |
[01:46:52]
[01:46:52] error[E0425]: cannot find function `Wrapping` in this scope
[01:46:52]   --> num/     num/wrapping.rs - num::wrapping::Wrapping<u64>::next_power_of_two (line 707)
---
[01:46:52] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "test" "--target" "x86_64-unknown-linux-gnu" "--release" "--locked" "--color" "always" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/checkout/src/libstd/Cargo.toml" "-p" "core" "--" "--quiet"
[01:46:52] expected success, got: exit code: 101
[01:46:52]
[01:46:52]
[01:46:52] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:46:52] Build completed unsuccessfully in 0:49:26
[01:46:52] Makefile:58: recipe for target 'check' failed
[01:46:52] make: *** [check] Error 1

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN.

[scottmcm]

Sorry, @clarcharr; apparently I shouldn't try to do a quick fix before leaving for work. Hopefully this time I got it right (as I waited for the annoying stage2 build for rustdoc, and the doctests passed locally).

[clarfonthey]

@scottmcm No worries; thanks for the changes. :)

[pietroalbini]

Ping from triage @SimonSapin! This PR needs your review.

[SimonSapin]

• signum: looks good
• abs: implementation looks good, but the doc-comment needs to say more. Please copy the paragraph (and example) from e.g. i32::wrapping_abs.
• is_positive, is_negative, is_power_of_two: the premise of Tracking issue for integer methods for Wrapping #32463 is that Wrapping(x.0.foo()) is a lot more cumbersome than x.foo(), but for methods returning a boolean x.0.foo() doesn’t seem as bad. So I don’t know if adding these methods on Wrapping is really useful. What do you think?
• next_power_of_two, wrapping_next_power_of_two: do you have a use case for this? I have a hard time imagining how this would be useful. It looks like I included in the list in Tracking issue for integer methods for Wrapping #32463 two years ago, but the dubiousness-question-mark says I probably didn’t look at it too closely.

[clarfonthey]

As far as the docs go, I was planning on moving these docs to use doc_comment! anyway, for consistency with the primitive docs. When I do that I'll simply copy the documentation for wrapping_abs over in its entirety, modifying the examples.

As far as the boolean methods: I personally agree, although I'd use #44724 as a precedent for these being there. There is absolutely no use case for changing the endianness of a single byte, but having the methods exist on all integer types makes creating your own traits a lot easier, as you won't have to handle i8 and u8 separately. I imagine that adding these boolean methods to Wrapping<T> would also be useful for a similar reason. That said, if you would rather not have them, I'd be more than willing to remove them.

For the usefulness of wrapping_next_power_of_two, I'll let @scottmcm answer because I've personally not used either method.

[scottmcm]

I think these are all consistency arguments, making sure that replacing uN with wN just works and that everything has the full foo(), checked_foo(), and wrapping_foo(). For example,

Wrapped division on unsigned types is just normal division. There's no way wrapping could ever happen. This function exists, so that all operations are accounted for in the wrapping operations.
~ https://doc.rust-lang.org/std/primitive.u32.html#method.wrapping_div

And like how one of the arguments for Ord::min was "I can just change my float code to integer code and it works, no need to replace a.min(b) with cmp::min(a, b)".

[SimonSapin]

I hear the argument that Wrapping should have some next_power_of_two method for consistency, but its proposed behavior seems more like a footgun than anything you’d ever want (though I could be completely wrong). Zero is neither a power of two, nor after ("next" to) the original value.

[clarfonthey]

Perhaps wrapping to one might be a better solution?

[scottmcm]

Well, the next power of two after 200 is definitely 256, and 256 = 0 mod 256, so I do think that wrapping to 0 is the correct output. And I think "doesn't give you a power of two" is no more surprising or a footgun than abs not giving you a non-negative number.

.wrapping_next_power_of_two().wrapping_sub(1) is actually useful, since it never overflows.

[SimonSapin]

I feel like we’re all making suppositions on a theoretical basis here, and maybe we’d better off not add this method until someone comes along who actually wants to use it. Then we can look at the use case and see what behavior is most useful and least of a footgun.

[bors]

☔ The latest upstream changes (presumably #49939) made this pull request unmergeable. Please resolve the merge conflicts.

[pietroalbini]

Ping from triage! What's the status on this?

[shepmaster]

Thanks for the PR @clarcharr ! Since we haven't heard from you in a few weeks, I'm going to go ahead and close this PR for now to keep the queue tidy. If you have time to address the feedback, we'd love for you to reopen this PR!

[clarfonthey]

I finally got around to doing what I wanted for this PR, so, I'm going to open it up again. This adds all of the missing methods from the tracking issue, and uses doc_comment!, copying the examples from the primitives themselves when available.

[clarfonthey]

Err, I can't actually open it, so, I'll let @shepmaster or someone else do it.

(If it makes more sense to open a new PR, I'll do that.)

[kennytm]

@clarcharr It can't be reopened because the branch has been updated. Please open a new PR.

[shepmaster]

because the branch has been updated.

Well, that's annoying. We should probably warn people about that in our triage message. Sorry @clarcharr !