Crate flex_alloc

Data structures with extra flexible storage.

This crate provides highly flexible container types (currently Box, Cow, and Vec) which mimic the API provided in std, with allocation flexibility going beyond what is supported by unstable features such as allocator-api.

Both no-std and no-alloc environments are supported.

Highlights

• Optional alloc support, such that application may easily alternate between fixed buffers and heap allocation.
• Custom allocator implementations, including the ability to spill from a small stack allocation to a heap allocation.
• Additional fallible update methods, allowing for more ergonomic fixed size collections and handling of allocation errors.
• const initializers.
• Support for inline collections.
• Custom index types and growth behavior to manage memory usage.

Feature flags

• The std flag (off by default) enables compatibility with the std::error::Error trait for error types, adds io::Write support to Vec, and also enables the alloc feature.
• With the alloc feature (on by default), access to the global allocator is enabled, and default constructors for allocated containers (such as Vec::new) are supported.
• The allocator-api2 feature enables integration with the allocator-api2 crate, which offers support for the allocator-api feature set on stable Rust. This can allow for allocators implementing the API to be passed to Vec::new_in.
• The nightly feature enables compatibility with the unstable Rust allocator-api feature. This requires a nightly Rust compiler build.
• The zeroize feature enables integration with the zeroize crate, including a zeroizing allocator. This can be used to automatically zero out allocated memory for allocated types, including the intermediate buffers produced during resizing in the case of Vec.

Modules

alloc

Support for memory allocation.

borrow

Support for flexibility over owned or borrowed collections.

boxed

Support for values contained within allocated memory.

capacity

Types used to specify indexes, ranges, lengths, and capacities of collections.

storage

Backing storage types for collections.

vec

Support for generic vector structures containing a (generally) resizable, contiguous array of items.

Macros

vec

Allocate a new Vec instance with optional initial items.

Structs

UpdateError

An error raised by collection update operations when appropriate storage was not available. Includes an associated value that could not be stored or converted.

Enums

StorageError

An enumeration of error types raised by storage implementations.