------- Comment #7 from jason at gcc dot gnu dot org 2010-04-18 15:08 ------- That is, the problem is that template_arity_impl calls arity_helper(type_wrapper<F>,...) in a way that uses arg-dependent lookup, which means looking up arity_helper within F, which means instantiating F, which in this case is use_simple_repeat. 4.5 is the first version of G++ to implement this behavior. As for 43608, the fix is to change template_arity_impl to not use arg-dependent lookup.
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43775