Merge pull request #201 from zakarumych/main

Use allocator-api through allocator-api2 crate

.github/workflows/rust.yaml

@@ -14,7 +14,7 @@ jobs:
   build:
     strategy:
       matrix:
-        rust_channel: ["stable", "beta", "nightly", "1.60.0"]
+        rust_channel: ["stable", "beta", "nightly", "1.63.0"]
         feature_set: ["--features collections,boxed"]
         include:
           - rust_channel: "nightly"

CHANGELOG.md

@@ -4,12 +4,17 @@ Released YYYY-MM-DD.
 
 ### Added
 
-* TODO (or remove section if none)
+* New `"allocator-api2"` feature enables use of allocator API on stable.
+  This feature uses a crate that mirrors the API of
+  unstable `allocator_api` feature.
+  If feature is enabled, references to `Bump` implement
+  `allocator_api2::Allocator`.
+  This allows `Bump` to be used as allocator for collection types from
+  `allocator-api2` and any other crates that support `allocator-api2`.
 
 ### Changed
 
-* The minimum supported Rust version (MSRV) is now 1.60.0.
-* TODO (or remove section if none)
+* The minimum supported Rust version (MSRV) is now 1.63.0.
 
 ### Deprecated
 

Cargo.toml

@@ -30,6 +30,9 @@ name = "try_alloc"
 path = "tests/try_alloc.rs"
 harness = false
 
+[dependencies]
+allocator-api2 = { version = "0.2.8", default-features = false, optional = true, features = ["alloc"] }
+
 [dev-dependencies]
 quickcheck = "1.0.3"
 criterion = "0.3.6"

README.md

@@ -209,7 +209,7 @@ v.push(2);
 
 #### Minimum Supported Rust Version (MSRV)
 
-This crate is guaranteed to compile on stable Rust **1.60** and up. It might
+This crate is guaranteed to compile on stable Rust **1.63** and up. It might
 compile with older versions but that may change in any new patch release.
 
 We reserve the right to increment the MSRV on minor releases, however we will

src/lib.rs

@@ -2,10 +2,7 @@
 #![deny(missing_debug_implementations)]
 #![deny(missing_docs)]
 #![no_std]
-#![cfg_attr(
-    feature = "allocator_api",
-    feature(allocator_api, nonnull_slice_from_raw_parts)
-)]
+#![cfg_attr(feature = "allocator_api", feature(allocator_api))]
 
 #[doc(hidden)]
 pub extern crate alloc as core_alloc;
@@ -26,9 +23,13 @@ use core::ptr::{self, NonNull};
 use core::slice;
 use core::str;
 use core_alloc::alloc::{alloc, dealloc, Layout};
+
 #[cfg(feature = "allocator_api")]
 use core_alloc::alloc::{AllocError, Allocator};
 
+#[cfg(all(feature = "allocator-api2", not(feature = "allocator_api")))]
+use allocator_api2::alloc::{AllocError, Allocator};
+
 pub use alloc::AllocErr;
 
 /// An error returned from [`Bump::try_alloc_try_with`].
@@ -1886,11 +1887,13 @@ unsafe impl<'a> alloc::Alloc for &'a Bump {
     }
 }
 
-#[cfg(feature = "allocator_api")]
+#[cfg(any(feature = "allocator_api", feature = "allocator-api2"))]
 unsafe impl<'a> Allocator for &'a Bump {
     fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
         self.try_alloc_layout(layout)
-            .map(|p| NonNull::slice_from_raw_parts(p, layout.size()))
+            .map(|p| unsafe {
+                NonNull::new_unchecked(ptr::slice_from_raw_parts_mut(p.as_ptr(), layout.size()))
+            })
             .map_err(|_| AllocError)
     }
 
@@ -1905,7 +1908,9 @@ unsafe impl<'a> Allocator for &'a Bump {
         new_layout: Layout,
     ) -> Result<NonNull<[u8]>, AllocError> {
         Bump::shrink(self, ptr, old_layout, new_layout)
-            .map(|p| NonNull::slice_from_raw_parts(p, new_layout.size()))
+            .map(|p| unsafe {
+                NonNull::new_unchecked(ptr::slice_from_raw_parts_mut(p.as_ptr(), new_layout.size()))
+            })
             .map_err(|_| AllocError)
     }
 
@@ -1916,7 +1921,9 @@ unsafe impl<'a> Allocator for &'a Bump {
         new_layout: Layout,
     ) -> Result<NonNull<[u8]>, AllocError> {
         Bump::grow(self, ptr, old_layout, new_layout)
-            .map(|p| NonNull::slice_from_raw_parts(p, new_layout.size()))
+            .map(|p| unsafe {
+                NonNull::new_unchecked(ptr::slice_from_raw_parts_mut(p.as_ptr(), new_layout.size()))
+            })
             .map_err(|_| AllocError)
     }