Use 'class' or 'typename' for template parameters? [duplicate]

Question

Stan Lippman talked about this here. I thought it was interesting.

Summary: Stroustrup originally used class to specify types in templates to avoid introducing a new keyword. Some in the committee worried that this overloading of the keyword led to confusion. Later, the committee introduced a new keyword typename to resolve syntactic ambiguity, and decided to let it also be used to specify template types to reduce confusion, but for backward compatibility, class kept its overloaded meaning.

According to Scott Myers, Effective C++ (3rd ed.) item 42 (which must, of course, be the ultimate answer) - the difference is "nothing".

Advice is to use "class" if it is expected T will always be a class, with "typename" if other types (int, char* whatever) may be expected. Consider it a usage hint.

As an addition to all above posts, the use of the class keyword is forced (up to and including C++14) when dealing with template template parameters, e.g.:

template <template <typename, typename> class Container, typename Type>
class MyContainer: public Container<Type, std::allocator<Type>>
{ /*...*/ };

In this example, typename Container would have generated a compiler error, something like this:

error: expected 'class' before 'Container'

I prefer to use typename because I'm not a fan of overloaded keywords (jeez - how many different meanings does static have for various different contexts?).

There is a difference, and you should prefer class to typename.

But why?

typename is illegal for template template arguments, so to be consistent, you should use class:

template<template<class> typename MyTemplate, class Bar> class Foo { };    //  :(
template<template<class>    class MyTemplate, class Bar> class Foo { };    //  :)

In response to Mike B, I prefer to use 'class' as, within a template, 'typename' has an overloaded meaning, but 'class' does not. Take this checked integer type example:

template <class IntegerType>
class smart_integer {
public: 
    typedef integer_traits<Integer> traits;
    IntegerType operator+=(IntegerType value){
        typedef typename traits::larger_integer_t larger_t;
        larger_t interm = larger_t(myValue) + larger_t(value); 
        if(interm > traits::max() || interm < traits::min())
            throw overflow();
        myValue = IntegerType(interm);
    }
}

larger_integer_t is a dependent name, so it requires 'typename' to preceed it so that the parser can recognize that larger_integer_t is a type. class, on the otherhand, has no such overloaded meaning.

That... or I'm just lazy at heart. I type 'class' far more often than 'typename', and thus find it much easier to type. Or it could be a sign that I write too much OO code.