Daryle Walker wrote:
The way around it is to add an "unused" EnableIf template parameter to the constructor template that cancels the template when Args is a single argument and the argument's type is MyType.
How about using SFINAE to `noexcept` operator as in http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48468 ? template <typename... T, bool NoExcept = BOOST_NOEXCEPT_EXPR(......)> explicit BOOST_CONSTEXPR base_from_member( T&& ...x ) BOOST_NOEXCEPT_IF( NoExcept ) // no std::is_nothrow_constructible... : member( static_cast<T&&>(x)... ) // ...nor std::forward needed {} This seems a bit simpler, but of course, it might be a personal taste ;) In `bool NoExcept = BOOST_NOEXCEPT_EXPR(...…)`, we have to use `MemberType(boost::declval<T>()...)` instead of `MemberType(static_cast<T&&>(x)...)`. P.S. I requested adding `noexcept` to `boost::declval`. https://svn.boost.org/trac/boost/ticket/6570 Regards, Michel