alt future ? = ]

the_future_is_near.cs

interface IProductService
{
    Future<int> GetPrice(string id);
    Future<double> GetDiscount (int qty);
}

Future<int> GetQuote(string id, int qty)
{
    var service = _activator.Get<IProductService>();

    return 
        Future
            .Of(
                service.GetPrice (id), 
                service.GetDiscount (qty))
            .WhenAvailable(
                (price, discount)=> (int)(price * qty * discount));
}

from price in service.GetPrice (id)
from discount in service.GetDiscount(qty)
select (int) (price * qty * discount)