This library implements C++20 coroutine support for Unreal Engine 5. It complements the engine's (as of 5.0) experimental coroutine support with additional features such as easy authoring of BP latent actions.

Download the release that you wish to use from the Releases page, extract it to your project's Plugins folder and in case you downloaded a source code zip, rename the folder that it contains to just UE5Coro so that you end up with YourProject\Plugins\UE5Coro\UE5Coro.uplugin.

In modules where you wish to use coroutines, add or change this line in the corresponding Build.cs file to enable the required language features:

CppStandard = CppStandardVersion.Cpp20;

Add "UE5Coro" to your dependency module names in the same Build.cs file, enable the plugin in the Unreal editor, and you're ready to go!

Click these links for the detailed description of the main features provided by this plugin, or keep reading for a quick overview.

• Generators are caller-controlled and co_yield a sequence of objects, also known as iterators in C#.
• Async coroutines control their own resumption by co_awaiting various awaiter objects. They can be used to implement BP latent actions or as a generic fork in code execution like AsyncTask, but not necessarily involving multithreading.
• Overview of built-in awaiters that you can use with async coroutines.

Generators can be used to return an arbitrary number of items from a function without having to pass them through temp arrays, etc. In C# they're known as iterators.

Returning UE5Coro::TGenerator<T> makes a function coroutine enabled, supporting co_yield:

using namespace UE5Coro;

TGenerator<FString> MakeParkingSpaces(int Num)
{
    for (int i = 1; i <= Num; ++i)
        co_yield FString::Printf(TEXT("🅿️ %d"), i);
}

// Elsewhere
for (const FString& Str : MakeParkingSpaces(123))
    Process(Str);

Return FAsyncCoroutine from a function (regular or UFUNCTION) to make it coroutine enabled and support co_await. There's special handling in place that automatically implements BP latent actions for you but it works for everything:

using namespace UE5Coro;

UFUNCTION(BlueprintCallable, Meta = (Latent, LatentInfo = "LatentInfo"))
FAsyncCoroutine UExampleFunctionLibrary::K2_Foo(int EpicPleaseFixUE22342,
                                                FLatentActionInfo LatentInfo)
{
    // You can freely hop between threads:
    co_await Async::MoveToThread(ENamedThreads::AnyBackgroundThreadNormalTask);
    DoExpensiveThingOnBackgroundThread();
    co_await Async::MoveToGameThread();

    // Delay for 1 more second without blocking the game thread:
    co_await Latent::Seconds(1.0f);

    // The BP node will fire its latent exec pin once control leaves the coroutine.
}