Re: [Boost-users] [type_traits]: is_boost_optional?

Subject: Re: [Boost-users] [type_traits]: is_boost_optional?
From: Roman Perepelitsa (roman.perepelitsa_at_[hidden])
Date: 2010-09-01 08:13:51

2010/9/1 Roland Bock <rbock_at_[hidden]>

> Hi,
>
> is there something in Boost.TypeTraits (or somewhere else) that allows me
> to check if a type is a boost::optional?
>
> I'd like to do something like this:
>
> template<typename T>
> typename enable_if<is_boost_optional<T> >, T::value_type>::type foo(const
> T&);

You can use is_instance_of from lambda library (see
boost/lambda/detail/is_instance_of.hpp). It's not part of public interface
though, so use it on your own risk.

  template <class T>
  struct is_boost_optional : boost::lambda::is_instance_of_1<T,
boost::optional> {}

Roman Perepelitsa.