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)

    }

Unexecuted instantiation: hashbrown::raw::inner::alloc::inner::do_alloc::<hashbrown::raw::inner::alloc::inner::Global>

Unexecuted instantiation: hashbrown::raw::inner::alloc::inner::do_alloc::<hashbrown::raw::inner::alloc::inner::Global>

Unexecuted instantiation: hashbrown::raw::inner::alloc::inner::do_alloc::<hashbrown::raw::inner::alloc::inner::Global>

Unexecuted instantiation: hashbrown::raw::inner::alloc::inner::do_alloc::<_>

}