| pub(crate) use self::inner::{do_alloc, Allocator, Global}; |
| |
| // Nightly-case. |
| // Use unstable `allocator_api` feature. |
| // This is compatible with `allocator-api2` which can be enabled or not. |
| // This is used when building for `std`. |
| #[cfg(feature = "nightly")] |
| mod inner { |
| use crate::alloc::alloc::Layout; |
| pub use crate::alloc::alloc::{Allocator, Global}; |
| use core::ptr::NonNull; |
| |
| #[allow(clippy::map_err_ignore)] |
| pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { |
| match alloc.allocate(layout) { |
| Ok(ptr) => Ok(ptr.as_non_null_ptr()), |
| Err(_) => Err(()), |
| } |
| } |
| } |
| |
| // Basic non-nightly case. |
| // This uses `allocator-api2` enabled by default. |
| // If any crate enables "nightly" in `allocator-api2`, |
| // this will be equivalent to the nightly case, |
| // since `allocator_api2::alloc::Allocator` would be re-export of |
| // `core::alloc::Allocator`. |
| #[cfg(all(not(feature = "nightly"), feature = "allocator-api2"))] |
| mod inner { |
| use crate::alloc::alloc::Layout; |
| pub use allocator_api2::alloc::{Allocator, Global}; |
| use core::ptr::NonNull; |
| |
| #[allow(clippy::map_err_ignore)] |
| pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { |
| match alloc.allocate(layout) { |
| Ok(ptr) => Ok(ptr.cast()), |
| Err(_) => Err(()), |
| } |
| } |
| } |
| |
| // No-defaults case. |
| // When building with default-features turned off and |
| // neither `nightly` nor `allocator-api2` is enabled, |
| // this will be used. |
| // Making it impossible to use any custom allocator with collections defined |
| // in this crate. |
| // Any crate in build-tree can enable `allocator-api2`, |
| // or `nightly` without disturbing users that don't want to use it. |
| #[cfg(not(any(feature = "nightly", feature = "allocator-api2")))] |
| mod inner { |
| use crate::alloc::alloc::{alloc, dealloc, Layout}; |
| use core::ptr::NonNull; |
| |
| #[allow(clippy::missing_safety_doc)] // not exposed outside of this crate |
| pub unsafe trait Allocator { |
| fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()>; |
| unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout); |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct Global; |
| |
| unsafe impl Allocator for Global { |
| #[inline] |
| fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> { |
| unsafe { NonNull::new(alloc(layout)).ok_or(()) } |
| } |
| #[inline] |
| unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { |
| dealloc(ptr.as_ptr(), layout); |
| } |
| } |
| |
| impl Default for Global { |
| #[inline] |
| fn default() -> Self { |
| Global |
| } |
| } |
| |
| pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { |
| alloc.allocate(layout) |
| } |
| } |