IConsumer<T> public interface IConsumer<T> : IFunctional<Action<T>> Represents functional interface returning no value and accepting the single argument. Documentation Code using DotNext.Runtime.CompilerServices; using System; using System.Runtime.CompilerServices; namespace DotNext { [NullableContext(1)] public interface IConsumer<[Nullable(2)] in T> : IFunctional<Action<T>> { void Invoke(T arg); Action<T> IFunctional<Action<T>>.ToDelegate() { return Invoke; } } }