Re: [Boost-users] [mpl] pop_back<range_c> is forbidden?

Andriy Tylychko writes:

Reading "C++ Template Metaprogramming" book:

"Though not extensible, range_c supports pop_front and pop_back, because contracting a range is easy"

But following code doesn't work (at least using MSVC 8.0):

#include #include

using namespace boost::mpl;

typedef range_c r; typedef pop_back<r>::type p;

Can anybody explain?

I'm afraid you've found a discrepancy between what was planned and what was actually implemented: the current 'range_c' implementation simply does not provide the code required to make the above work. I've put the issue on the library's TODO list (http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?MPL_TODO_List). Patches are always welcome! Thanks for the report, -- Aleksey Gurtovoy MetaCommunications Engineering