Implementation of generic technology

There are many implementation methods for generic technology, such as templates and polymorphism.

The template is determined by the compile time, the polymorphism is determined by the runtime, and the others such as rtti are also determined by the runtime.

It is best to use a template. polymorphism depends on the Table query during running of virtual tables.

For example, if a class has a virtual method, the memory start address of the instance of this class is the virtual table address. You can forcibly convert the memory start address to int * to obtain the virtual table, then (int *) * (int *) gets the memory address of the first function in the virtual table, and converts it to the function type forcibly, that is, it can be called to verify the virtual table mechanism.