jhpratt/standback

Backported standard Rust library to older compilers.

standback's Issues

Support std::char::UNICODE_VERSION

Values of that constant depend on Rust version:

Rust 1.44: (13, 0, 0)
Rust 1.38 to 1.43: (12, 1, 0)
Rust 1.28 to 1.37: (11, 0, 0)

Fails to build on rustc 1.53.0-nightly (f82664191 2021-03-21)

See https://github.com/lambda-fairy/maud/runs/2162452518

error[E0432]: unresolved import `core::task::Wake`
   --> /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/standback-0.2.16/src/lib.rs:520:13
    |
520 |     pub use core::task::Wake;
    |             ^^^^^^^^^^^^----
    |             |           |
    |             |           help: a similar name exists in the module (notice the capitalization): `wake`
    |             no `Wake` in `task`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0432`.
error: could not compile `standback`

No Cargo.toml in shipped 0.2.12

Apologies if this is some infrastructure bug/race condition, I've just never seen it before.

$ cargo build
   Updating crates.io index
  Downloaded standback v0.2.12
error: failed to read `/tmp/cWTyyIj3_Y/vcheck_pl/cargo_1/.cargo/registry/src/github.com-1ecc6299db9ec823/standback-0.2.12/Cargo.toml`

Caused by:
  No such file or directory (os error 2)

$ curl -sL https://crates.io/api/v1/crates/standback/0.2.12/download | tar -zt
standback-0.2.12/CHANGELOG.md
standback-0.2.12/LICENSE-Apache
standback-0.2.12/LICENSE-MIT
standback-0.2.12/README.md
standback-0.2.12/build.rs
standback-0.2.12/src/lib.rs
standback-0.2.12/src/v1_32.rs
standback-0.2.12/src/v1_33/pin.rs
standback-0.2.12/src/v1_33.rs
standback-0.2.12/src/v1_34/try_from.rs
standback-0.2.12/src/v1_34.rs
standback-0.2.12/src/v1_35.rs
standback-0.2.12/src/v1_36/iterator_copied.rs
standback-0.2.12/src/v1_36/maybe_uninit.rs
standback-0.2.12/src/v1_36/poll.rs
standback-0.2.12/src/v1_36/waker.rs
standback-0.2.12/src/v1_36.rs
standback-0.2.12/src/v1_37.rs
standback-0.2.12/src/v1_38.rs
standback-0.2.12/src/v1_40.rs
standback-0.2.12/src/v1_41.rs
standback-0.2.12/src/v1_42.rs
standback-0.2.12/src/v1_43.rs
standback-0.2.12/src/v1_44.rs
standback-0.2.12/src/v1_45.rs
standback-0.2.12/src/v1_46.rs
standback-0.2.12/src/v1_47.rs
standback-0.2.12/src/v1_48.rs
standback-0.2.12/.cargo_vcs_info.json

And this indeed seems to suggest that somehow, Cargo.toml is missing from the published crate.

Please provide `IsTerminal`

To help people who want to use IsTerminal but their MSRV policy prevents it, please consider providing IsTerminal in standback.

`todo!` macro not re-exported from std

Using standback::todo only works with Rust < 1.40.

error[E0658]: use of unstable library feature 'extra_log_consts'

This error prevents my crate from building.

I fixed it by adding #![feature(extra_log_consts)] to standback's lib.rs

OS:

nightly-x86_64-pc-windows-msvc (default)
rustc 1.43.0-nightly (58b834344 2020-02-05)

Error log:

$ cargo build --release -j 4
   Compiling standback v0.2.8
   Compiling libz-sys v1.0.25
error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:612:37
    |
612 |         pub use core::f32::consts::{LOG10_2, LOG2_10};
    |                                     ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:612:37
    |
612 |         pub use core::f32::consts::{LOG10_2, LOG2_10};
    |                                     ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:612:46
    |
612 |         pub use core::f32::consts::{LOG10_2, LOG2_10};
    |                                              ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:612:46
    |
612 |         pub use core::f32::consts::{LOG10_2, LOG2_10};
    |                                              ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:620:37
    |
620 |         pub use core::f64::consts::{LOG10_2, LOG2_10};
    |                                     ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:620:37
    |
620 |         pub use core::f64::consts::{LOG10_2, LOG2_10};
    |                                     ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:620:46
    |
620 |         pub use core::f64::consts::{LOG10_2, LOG2_10};
    |                                              ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error[E0658]: use of unstable library feature 'extra_log_consts'
   --> D:\Users\mizu\.cargo\registry\src\github.com-1ecc6299db9ec823\standback-0.2.8\src\lib.rs:620:46
    |
620 |         pub use core::f64::consts::{LOG10_2, LOG2_10};
    |                                              ^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/50540
    = help: add `#![feature(extra_log_consts)]` to the crate attributes to enable

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0658`.
error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0658`.
error: could not compile `standback`.
warning: build failed, waiting for other jobs to finish...
error: could not compile `standback`.
warning: build failed, waiting for other jobs to finish...
error: build failed

`MaybeUninit` leads to UB

The current implementation of MaybeUninit in this crate leads to undefined behavior. The reason that mem::uninitialized was deprecated is because it can easily cause UB with even the most basic of uses. The solution to this problem was the MaybeUnint type, specifically because the type is an untagged union with the unit type, something that has been stable since (I believe) 1.19. The type defined in this crate does not have the union and is basically a wrapper around mem::uninitialized without any kind of warning.

If there is a reason that the version of MaybeUninit implemented in the standard library can't be used here (I do not know, I have not tried) then I believe this library should at the very least document that somewhere visible to users. Ideally, it should also document in the code as to why it cannot be implemented in the same way.