What is the difference between “template ” and “template ”? [duplicate]

Answer 1

In case of template template paramater

template  class Wrapper>
class Foo {
    //...
  private:
    Wrapper data;
};

You have to use class before classname. This is wrong:

template  typename Wrapper>

but this is ok:

template  class Wrapper>

In other cases they are interchangeable.