Struct RcBlock 

pub struct RcBlock<Closure> { /* private fields */ }

A reference-counted block wrapping a Rust closure.

This structure matches the Clang blocks ABI exactly, allowing Rust closures to be passed to Objective-C APIs that expect block parameters.

Implementations

impl<Closure> RcBlock<Closure>

pub unsafe fn new(closure: Closure, invoke: *const c_void) -> Self

Create a new block with the specified invoke function.

Safety

The invoke function pointer must have the correct calling convention and signature for the block type. The first parameter must be a pointer to the BlockLiteral.

pub unsafe fn new_heap(closure: Closure, invoke: *const c_void) -> Box<Self>

Create a new heap-allocated block with the specified invoke function.

This allocates the block on the heap so it can be safely passed to Objective-C APIs that retain the block. The returned pointer should be passed to as_heap_ptr() to get the block pointer.

Safety

The invoke function pointer must have the correct calling convention and signature for the block type.

pub fn as_ptr(&self) -> *const c_void

Get a pointer to the block literal to pass to Objective-C.

pub fn into_raw(self) -> *const c_void

Consume the block, preventing its destructor from running.

Use this after passing the block to Metal/Objective-C APIs that will retain the block internally. The block runtime will handle cleanup when the retain count reaches zero.

impl RcBlock<Box<dyn Fn() + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn() + Send + 'static,

Create a block from a closure taking no arguments.

impl RcBlock<Box<dyn Fn(*mut c_void) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void) + Send + 'static,

Create a block from a closure taking one pointer argument.

pub fn from_fn_heap<F>(f: F) -> HeapOneArgBlock

where F: Fn(*mut c_void) + Send + 'static,

Create a heap-allocated block from a closure taking one pointer argument.

Use this for blocks that need to outlive the current scope, such as completion handlers passed to Metal APIs.

impl RcBlock<Box<dyn Fn(*mut c_void, *mut c_void) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void, *mut c_void) + Send + 'static,

Create a block from a closure taking two pointer arguments.

This matches the C++ pattern:

using NewLibraryCompletionHandler = void (^)(MTL::Library*, NS::Error*);

impl RcBlock<Box<dyn Fn(*mut c_void, *mut c_void, *mut c_void) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void, *mut c_void, *mut c_void) + Send + 'static,

Create a block from a closure taking three pointer arguments.

This matches the C++ pattern:

using NewRenderPipelineStateWithReflectionCompletionHandler =
    void (^)(MTL::RenderPipelineState*, MTL::RenderPipelineReflection*, NS::Error*);

impl RcBlock<Box<dyn Fn(*mut c_void, u64) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void, u64) + Send + 'static,

Create a block for SharedEvent notifications.

This matches the C++ pattern for event signaling.

impl RcBlock<Box<dyn Fn(*mut c_void, usize) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void, usize) + Send + 'static,

Create a block for buffer deallocation.

The closure receives the buffer pointer and its size.

impl RcBlock<Box<dyn Fn(*mut c_void, *mut c_void, isize, *mut c_void) + Send>>

pub fn from_fn<F>(f: F) -> Self

where F: Fn(*mut c_void, *mut c_void, isize, *mut c_void) + Send + 'static,

Create a block for log handling.

The closure receives (subsystem, category, level, message).