Use 'class' or 'typename' for template parameters? [duplicate]
Solution 1:
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.
Solution 2:
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.