On Thu, May 26, 2011 at 8:34 AM, tymofey <tymofey@qip.ru> wrote:
While experimenting with varidic templates of the upcoming standard i discovered that quite often one would need to extract a type from parameter pack at specified position. While the task is trivial it would be quite handy to have a ready tool for this purpose, rather that specifying one yourself every time.
You can find source code consisting of a single header at Vault/Utilities/type_at.hpp
The usage is simple:
boost::type_at<index, some_type_0, some_type_1, some_type_2, some_type_n>::type
corresponds to some_type_index where index is in range [0..n]. For example:
boost::type_at<2, int, float, char, long>::type
corresponds to char.
Forgive me if I'm missing the point, but isn't this essentially Boost.MPL's 'at' metafunction? - Rob.