Document features

Cargo.toml

@@ -17,6 +17,6 @@ categories = ["no-std", "no-std::no-alloc"]
 
 [workspace.dependencies]
 proc-macro2 = { version = "1", default-features = false }
-ptr_meta_derive = { version = "0.3.0-alpha.2", default-features = false, path = "ptr_meta_derive" }
+ptr_meta_derive = { version = "=0.3.0-alpha.3", default-features = false, path = "ptr_meta_derive" }
 syn = { version = "2", default-features = false }
 quote = { version = "1", default-features = false }

ptr_meta/src/lib.rs

@@ -23,8 +23,8 @@
 //! `ptr_meta` provides inherent implementations for many builtin types:
 //!
 //! - All [`Sized`] types implement [`Pointee`] via a blanket implementation.
-//! - `slice`s and `str`s
-//! - `CStr` and `OsStr` (requires `std`)
+//! - `slice`, `str`, and `CStr`
+//! - `OsStr` (requires `std`)
 //! - `dyn Any`, optionally with `+ Send` and/or `+ Sync`
 //! - `dyn Error`, optionally with `+Send` and/or `+ Sync` (requires `std`)
 //!
@@ -64,6 +64,12 @@
 //!
 //! Note that this will not produce implementations for `Trait + Send + Sync`.
 //!
+//! ## Features
+//!
+//! - `derive`: Re-exports the macros from `ptr_meta_derive`. Enabled by
+//!   default.
+//! - `std`: Enables additional impls for `std` types. Enabled by default.
+//!
 //! ## Example
 #![doc = include_str!("../example.md")]
 #![deny(
@@ -86,6 +92,7 @@
 mod impls;
 
 use core::{
+    ffi::CStr,
     fmt,
     hash::{Hash, Hasher},
 };
@@ -147,17 +154,16 @@ unsafe impl Pointee for str {
     type Metadata = usize;
 }
 
-#[cfg(feature = "std")]
 // SAFETY: `CStr` pointers have a `usize` representing the length of the
 // C-string slice in bytes (nul included) as their metadata.
-unsafe impl Pointee for ::std::ffi::CStr {
+unsafe impl Pointee for CStr {
     type Metadata = usize;
 }
 
 #[cfg(feature = "std")]
 // SAFETY: `OsStr` pointers have a `usize` representing the length of the
 // string in bytes as their metadata.
-unsafe impl Pointee for ::std::ffi::OsStr {
+unsafe impl Pointee for std::ffi::OsStr {
     type Metadata = usize;
 }
 

ptr_meta_derive/src/lib.rs

@@ -14,7 +14,7 @@ use self::attributes::Attributes;
 ///
 /// Additional arguments can be specified using attributes.
 ///
-/// `#[ptr_meta(...)]` takes the following arguments:
+/// `#[ptr_meta(...)]` accepts the following arguments:
 ///
 /// - `crate = ...`: Chooses an alternative crate path to import ptr_meta from.
 #[proc_macro_derive(Pointee, attributes(ptr_meta))]