[boost] [type_erasure] Force any to have typedef

Subject: [boost] [type_erasure] Force any to have typedef
From: Benedek Thaler (thalerbenedek_at_[hidden])
Date: 2014-07-09 05:49:14

Hi,

Assume I have the following function template:

template <typename Container>
typename Container::value_type get_front(const Container& c)
{
  return c.front();
}

Is there a way I can force type_erasure::any<> to have a `value_type`
typedef? I can create a concept which requires the underlying type to have
it, but I'd like to make `any` to have such a typedef.

Thanks,
Benedek