BorrowingUnaryCallable
Defines safe readonly invocation borrowing one retained input item.
Module std.iteration
import std.iteration;Public declaration contracts and authored examples. A page can document several related symbols. Implementation bodies are excluded.
BorrowingUnaryCallable
pub concept BorrowingUnaryCallable<Self, T, R>Defines safe readonly invocation borrowing one retained input item.
Authored objects provide public readonly Invoke; generated lambdas satisfy the authenticated canonical witness. The borrowed argument cannot authorize moving or mutating the payload. Exact result/access and safety are preserved. Concrete captures use ordinary lifecycle; no box, allocation, lock or backing retention is added. Serialize callback use when its backing requires it. Self: Concrete callback/environment type. T: Retained source payload type; reference payloads keep exact alias rules. R: Exact callback output type. Warning: Borrowed capture and output backing must remain valid through use.
BorrowingUnaryCallable.Invoke
requires readonly fn Invoke(Item: readonly T&) -> R;Invokes a safe observer on readonly access to one live payload. Item: Retained item, borrowed synchronously and never implicitly copied. Return: Exact result with its original ownership/access requirements.