pw::async2::DerivedValueProvider< DerivedFuture > Class Template Reference

Overview

template<typename DerivedFuture>
class pw::async2::DerivedValueProvider< DerivedFuture >

A generic provider that vends user-defined derived futures.

DerivedValueProvider allows attaching custom parameters to requests by using a class derived from ValueFuture. This enables the provider to inspect the parameters (e.g., requested size) and conditionally fulfill requests via ResolveIf.

Template Parameters

DerivedFuture

The user-defined future type. It must inherit from ValueFuture<T> and provide a constructor that accepts ValueFuture<T>&& as its first argument.

Inheritance diagram for pw::async2::DerivedValueProvider< DerivedFuture >:

Public Member Functions
template<typename... Args>
DerivedFuture	Get (Args &&... args)
	Vends a derived future.
template<typename... Args>
std::optional< DerivedFuture >	TryGet (Args &&... args)
	Vends a derived future if none is currently pending.
template<typename F >
bool	ResolveIf (F &&callback)

Member Function Documentation

ResolveIf()

template<typename DerivedFuture >

template<typename F >

bool pw::async2::DerivedValueProvider< DerivedFuture >::ResolveIf ( F &&  callback )

inline

Atomically inspects the derived future and resolves it if the callback returns a value indicating fulfillment.

The callback receives a reference to the DerivedFuture and should return a value indicating whether the request can be fulfilled:

• For non-void futures (producing T), the callback should return std::optional<T>. Returning std::nullopt leaves the future pending.
• For void futures, the callback should return bool. Returning false leaves the future pending.

Parameters

callback

A callable (lambda, function pointer, etc.) invoked with a reference to the DerivedFuture.

Returns

true if the future was resolved, false otherwise.

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The documentation for this class was generated from the following file:

• pw_async2/public/pw_async2/value_future.h