Static polymorphism definition and implementation [closed]

Answer 1

1. Static polymorphic behavior is type polymorphism that occurs at compile time rather than run time.
2. Yes.
3. UML is about how classes interact at runtime -- I don't believe there's a UML format for describing templates, but I could be wrong.
4. As far as I am aware it is C++ specific, but I'm not positive given that I've not used every language ever invented. :) That said, JIT'd languages like C# and Java often are very good at removing the performance impact of indirect calls in some cases using information gleaned at runtime rather than at compile time. Whether this is at compile time or not is kind of up on the air though... after all, it is called a Just-In-Time Compiler.
5. The main benefit is simply performance. Runtime polymorphism can do everything static polymorphism can do (in fact it can do more), but it carries the cost of indirect calls (which can be expensive if there are enough of 'em)

Now, templates themselves have many uses beyond achieving compile time polymorphism -- for example the SFINAE magic that makes boost::bind work is certainly not polymorphic -- it's merely there in order to smooth over inconsistencies in the language itself.

Answer 2

How do we define static polymorphism in general?

The best way to understand it using examples. Policy Based Design is one example of static polymorphism. And in my opinion, it's very powerful technique to achieve static polymorphism.

Another example is, Curiously recurring template pattern (CRTP) which is also powerful technique.

Answer 3

2. No. In addition to templates, the method oveloading is also - static polymorphism. https://en.wikipedia.org/wiki/Function_overloading