Remove cap-async-std. (#399)

* Remove cap-async-std.

The underlying async-std crate has been discontinued, so discontinue the
cap-async-std crate as well.

Fixes #393.

* Remove the async-io pin from CI.

* Remove polling too.

Author: sunfishcode

.github/workflows/main.yml

@@ -375,8 +375,6 @@ jobs:
     - name: Use specific dependency versions for Rust 1.63 compatibility.
       run: |
         cargo update --package=once_cell --precise=1.20.3
-        cargo update --package=async-io --precise=2.5.0
-        cargo update --package=polling --precise=3.10.0
 
     # Don't use --all-features because some of the features have dependencies
     # that don't work on newer Rust versions.

Cargo.toml

@@ -17,9 +17,7 @@ exclude = ["/.*"]
 rust-version = "1.63"
 
 [dev-dependencies]
-async-std = { version = "1.13.0", features = ["attributes", "io_safety"] }
 anyhow = "1.0.37"
-cap-async-std = { path = "cap-async-std", version = "3.4.5" }
 cap-fs-ext = { path = "cap-fs-ext", version = "3.4.5" }
 cap-net-ext = { path = "cap-net-ext", version = "3.4.5" }
 cap-directories = { path = "cap-directories", version = "3.4.5" }
@@ -56,23 +54,14 @@ fs_utf8 = [
     "cap-fs-ext/fs_utf8",
     "cap-tempfile/fs_utf8",
 ]
-async_std_fs_utf8 = [
-    "cap-async-std/fs_utf8",
-    "cap-fs-ext/async_std_fs_utf8"
-]
 arf_strings = [
     "cap-std/arf_strings",
     "cap-fs-ext/arf_strings",
     "cap-tempfile/arf_strings",
 ]
-async_std_arf_strings = [
-    "cap-async-std/arf_strings",
-    "cap-fs-ext/async_std_arf_strings"
-]
 
 [workspace]
 members = [
-  "cap-async-std",
   "cap-fs-ext",
   "cap-net-ext",
   "cap-directories",

README.md

@@ -17,7 +17,6 @@ The `cap-std` project is organized around the eponymous [`cap-std`] crate, and
 develops libraries to make it easy to write capability-based code, including:
 
  - [`cap-std`] itself, which provides capability-based versions of `std` APIs
- - [`cap-async-std`], which is to [`async-std`] what `cap-std` is to `std`
  - [`cap-directories`] which provides capability-based access to
    [standard application directories]
  - [`cap-tempfile`], which provides capability-based access to
@@ -45,15 +44,13 @@ Linux.
 [CWE-22]: https://cwe.mitre.org/data/definitions/22.html
 [2021 CWE Top 25 Most Dangerous Software Weaknesses]: https://cwe.mitre.org/top25/archive/2021/2021_cwe_top25.html
 [`cap-std`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-std/README.md
-[`cap-async-std`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-async-std/README.md
 [`cap-directories`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-directories/README.md
 [`cap-tempfile`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-tempfile/README.md
 [`cap-fs-ext`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-fs-ext/README.md
 [`cap-time-ext`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-time-ext/README.md
 [`cap-rand`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-rand/README.md
 [`cap-net-ext`]: https://github.com/bytecodealliance/cap-std/blob/main/cap-net-ext/README.md
 [`cap_std::fs`]: https://docs.rs/cap-std/latest/cap_std/fs/index.html
-[`async-std`]: https://docs.rs/async-std/
 [standard application directories]: https://docs.rs/directories-next/
 [temporary directories]: https://docs.rs/tempfile/
 [random number generators]: https://docs.rs/rand/