Crate memapi2 

A small, no_std/no_alloc-friendly memory allocation interface for managing raw buffers.

This crate provides explicit layouts, a split allocator trait stack, and structured errors. It is no_std by default but relies on the alloc crate unless no_alloc is enabled. Enable std for system allocator integrations and os_err_reporting for richer diagnostics.

Core traits

• Alloc, Dealloc, Grow, Shrink, Realloc
• Convenience aliases: BasicAlloc and FullAlloc
• Optional mutable variants (alloc_mut_traits): AllocMut, DeallocMut, GrowMut, ShrinkMut, ReallocMut, BasicAllocMut, FullAllocMut
• Optional scoped allocations (alloc_temp_trait): AllocTemp

Types and errors

• Layout: crate layout type (with conversion to/from StdLayout unless no_alloc is enabled)
• DefaultAlloc: default allocator wrapper that delegates to the global allocator
• Errors: [Error], [Cause], [LayoutErr], [ArithErr], [ArithOp]

Data and type utilities

• data::type_props: SizedProps, PtrProps, VarSized, VarSizedStruct
• data::marker: UnsizedCopy, Thin, SizeMeta
• helpers: alignment, checked arithmetic, and pointer helpers

Allocator implementations

• DefaultAlloc (available unless no_alloc is enabled)
• std::alloc::System when the std feature is enabled
• c_alloc::CAlloc behind the c_alloc feature
• stack_alloc::StackAlloc behind the stack_alloc feature

Feature flags

• std: enables std integration (including std::alloc::System)
• os_err_reporting: best-effort OS error reporting via errno (requires std)
• alloc_mut_traits: mutable allocator trait variants
• alloc_temp_trait: scoped/temporary allocation trait
• c_alloc: C aligned_alloc-style allocator (c_alloc)
• stack_alloc: alloca-based allocator (stack_alloc)
• c_str: enables CStr-specific data traits in no_std (MSRV: 1.64)
• metadata: enables core::ptr::Pointee metadata support on nightly
• sized_hierarchy: enables core::marker::MetaSized support on nightly
• full, full_nightly: convenience bundles for docs/tests

Re-exports

pub use traits::*;

Modules

c_alloc

An allocator which uses C’s aligned_alloc set of allocation functions.

error

Errors that can occur during allocation.

helpers

Helpers that tend to be useful in other libraries as well.

stack_alloc

An allocator which uses C’s alloca/_alloca allocation function.

traits

The library’s main traits.

Structs

DefaultAlloc

Default allocator, delegating to the global allocator.

Layout

The layout of a block of memory in the form of its size and alignment in bytes.

Type Aliases

StdLayout

A type alias for alloc::alloc::Layout.