Struct CapturingBlock 

pub struct CapturingBlock {
    pub capture: *mut c_void,
    /* private fields */
}

A block carrying one pointer.

GlobalBlock captures nothing, which is all a block needs when the receiver only ever calls it — but a completion handler has to reach something, and the something differs per call. One captured word is enough for that: it is where the answer gets written.

_NSConcreteStackBlock with no copy/dispose helpers, so a receiver that copies it gets a memcpy and the capture comes along by value. That is only sound while the caller outlives the call, which is why this is used with a wait and not handed to anything that keeps it.

Fields

capture: *mut c_void

What the invoke function reads, at a fixed offset from the block.

Implementations

impl CapturingBlock

pub unsafe fn new(invoke: *const c_void, capture: *mut c_void) -> Self

Wrap invoke as a block carrying capture.

Safety

invoke must match the signature the receiver expects, taking the block itself first; and the block must outlive every call to it.