How to use std::async with void method with no parameters?

I'm assuming there's something very simple I'm missing about std::async. I'm trying to run 2 void methods asynchronously, with no return values.

#include <future>

class AsyncTestClass {

    public:
        void Initialize()
        {
            std::async(&AsyncTestClass::AsyncMethod1);
            std::async(&AsyncTestClass::AsyncMethod2);
        }

        void AsyncMethod1()
        {
            //time consuming operation
        }

        void AsyncMethod2()
        {
            //time consuming operation
        }
};

But get an error when calling my AsyncMethod1 or AsyncMethod2 within std:async:

Substitution failed: type 'typename std:conditional<sizeof....(ArgTypes) == 0, std::_Invoke_traits_Zero<void, typename std::decay.....is ill formed with _Fty = void (AsyncTestClass::*)(), _ArgTypes =

What is the proper usage of std:async with void, parameterless methods? The examples I see seem similar to how I'm using it, but it's not working for me.

AsyncTestClass::AsyncMethod1, being a non-static member function, can only be called if an instance of AsyncTestClass is supplied. You probably meant this:

std::async(&AsyncTestClass::AsyncMethod1, this)

This creates a std::future object whose value will be obtained by evaluating this->AsyncMethod1().

By the way, the return value of std::async should be assigned to a variable, otherwise the call will block. See std::async won't spawn a new thread when return value is not stored. If you have C++20, the compiler will catch this for you thanks to [[nodiscard]].