Hands-On Design Patterns with C++

Arguments for factory methods

In our simple example, the constructor took no arguments. Passing arguments to the constructor presents a bit of a problem if the constructors of different types have different parameters—after all, the MakeBuilding() function has to be declared with some specific parameters. One option that appears straightforward is to use functions with a variable number of arguments, or parameter packs—if you need a variable type and a number of arguments, use a function with variable arguments. It's a complex solution that looks much less attractive once you start implementing it. The simpler option is to create a parameter object with the hierarchy matching the hierarchy of the objects to create. Let's assume that, in our ...