C++ Knowledge share: 3 kinds of template parameters

Template non-type arguments

Such arguments must be constant expressions, addresses of functions or objects with external linkage, or addresses of static class members. Non-type template arguments are normally used to initialize a class or to specify the sizes of class members.

template<class T, int size> class MyTemplateClass{...}

Template template arguments

template<template<class T> class U> class B1

Template type arguments

C++11 - New features - Variadic templates