NullaryCallable

Requires a safe readonly zero-argument invocation with an exact result.

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Module std.iteration

import std.iteration;

Public declaration contracts and authored examples. A page can document several related symbols. Implementation bodies are excluded.

NullaryCallable

pub concept NullaryCallable<Self, R>

Requires a safe readonly zero-argument invocation with an exact result.

Concrete environments remain unboxed and keep their own capture/cleanup contracts. Generated closures receive canonical-package witness access only; user spellings do not gain private-method authority. No allocation, runtime dictionary or synchronization is introduced by concept satisfaction. Self: Concrete callback/environment representation. R: Exact return representation, including reference or void transport.

NullaryCallable.Invoke

requires readonly fn Invoke() -> R;

Invokes the safe callback without parameters through readonly access. Return: Exact result with its original ownership/reference contract.

Documentation snapshot: October 24, 2026 About versions ↗