asyncInstanceOf<T extends Object> static method

Future<T> asyncInstanceOf<T extends Object>(
  1. SingletonAsyncInstanceCaller<T> callback
)

Async singleton class like:

class A { A._(); // Private constructor

static Future get instance => Singleton.asyncInstanceOf(() async => A._()); }

Implementation

static Future<T> asyncInstanceOf<T extends Object>(
  SingletonAsyncInstanceCaller<T> callback,
) async {
  return _proxies[T] ??= await callback.call();
}