Re: [Boost-Users] Re: Newbie lambda question

Ian wrote:

Markus

Thanks for the reply, but no dice. The idea was to use the address of the current item as a quick and dirty counter modular counter, However this code:

std::for_each(begin, end, l::_1 = l::ll_static_cast<int>(_1) % 3);

does not take the address but the items value, and unfortunately this:

std::for_each(begin, end, l::_1 = l::ll_static_cast<int>(&_1) % 3);

does not compile. Now I could get a bit more realistic and just code the thing a bit cleaner like this:

int x = 0; for_each( lookup_, lookup_ + (sizeof(lookup_) / sizeof(unsigned int)), _1 = ++var(x) % 3 );

But that's kinda skirting around the real issue which is, if I can't use lambda to *directly* replace code that is trivial with a hand written loop, what chance when the complexity is raised a bit?

It is a feature that your original (nonportable) code cannot be replaced by a lambda expression. Why not just use the correct version? Or even better: template size_t array_size(T (&a) [N]) { return N; } int x = 0; std::generate_n(lookup_, array_size(lookup_), ++ll::var(x) % 3); You can even get rid of x by using std::generate_n(lookup_, array_size(lookup_), boost::bind<int>(++ll::_1 % 3, 0)); if you are using the CVS version of boost::bind; 1.30 doesn't approximate http://std.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1438.htm well.