2013/2/11 Adam Wulkiewicz <adam.wulkiewicz@gmail.com>
Krzysztof Czainski wrote:
I assume I can't change the Strategy or emplace_back()/resize() behavior
for just one particular varray object, can I?
I mean:
varray<int,5> a; varray<int,5> b;
I'd like to change the Strategy only for b, can I do that?
You may do it by partially specialize varray_traits for your strategy. Currently the varray allowing to pass user-defined strategy is implemented in the container_detail namespace. So it would look more or less like this:
namespace bc = boost::container;
// define my strategy template <typename V> struct my_strategy : public bc::container_detail::**strategy::def<V> {};
// specialize traits for my strategy namespace boost { namespace container { namespace container_detail {
template <typename V, typename C> struct varray_traits<V, C, my_strategy> : public varray_traits<V, C, strategy::def<V> > { typedef boost::true_type disable_trivial_init; };
}}}
/*...*/
// use non-default version of varray bc::container_detail::varray<**int, 5, my_strategy<int> > b;
Aha, so I just use the hidden in container_detail version of varray with 3 template parameters. Future alternative:
Currently settings like disable_trivial_init are hidden deeply inside details. However they might be a part of default Strategy concept. Assuming that varray was moved to the boost::container namespace the example would be shorter:
// define my strategy template <typename V> struct my_strategy : public bc::strategy::def<V> { typedef boost::true_type disable_trivial_init; };
/*...*/
// use non-default version of varray bc::varray<int, 5, my_strategy<int> > b;
Ok, then +1 for this option ;-) Thank you, Adam, for elaborating on this topic. Cheers, Kris