lagoon/range/sort.hpp

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#ifndef LAGOON_RANGE_SORT_1011291729_HPP
#define LAGOON_RANGE_SORT_1011291729_HPP

#include <lagoon/lagoon_fwd.hpp>
#include <lagoon/range/container.hpp>
#include <lagoon/range/std_range.hpp>
#include <cassert>
#include <algorithm>

LAGOON_NAMESPACE_BEGIN

namespace aux {

// Helper base class for sorted container_range copying
// the element from the range into a container by using
// the push_back member during the construction
struct rng2cntr_push_back
{
    rng2cntr_push_back(void) = default;

    template <class Range, class Container>
    inline rng2cntr_push_back(Range range, Container& container)
    {
        while(!range.empty())
        {
            container.push_back(range.front());
            range.step_front();
        }
    }
};

// Helper class for sorted container_range sorting
// the elements by using the given strict weak ordering
// functor passed as the first argument
struct vector_sorter
{
    template <typename StrictWeakOrdering, typename Vector>
    inline vector_sorter(StrictWeakOrdering sort, Vector& vec)
    {
        std::sort(vec.begin(), vec.end(), sort);
    }
};

// Base class for the sorted range adaptor
template <typename Range>
class sorted : public container_range<
    std::vector<shared<typename range_meta_object<Range>::type> >,
    rng2cntr_push_back,
    vector_sorter
>
{
private:
    typedef container_range<
        std::vector<shared<typename range_meta_object<Range>::type> >,
        rng2cntr_push_back,
        vector_sorter
    > base_class;
public:
    template <typename SortProc>
    sorted(const Range& rng, SortProc sort)
     : base_class(rng, sort)
    { }
};

} // namespace aux

#ifdef MIRROR_DOCUMENTATION_ONLY


template <class Range, typename SortProc>
UnspecifiedRange sort(Range range, SortProc sort_proc);
#else
template <class Range, typename SortProc>
inline aux::sorted<Range> sort(Range range, SortProc sort_proc)
{
    return aux::sorted<Range>(range, sort_proc);
}

// overload for unadapted Lagoon's meta-object ranges
template <class MetaObject, typename SortProc>
inline aux::sorted<range<MetaObject> >
sort(range<MetaObject> mo_range, SortProc sort_proc)
{
    return aux::sorted<range<MetaObject> >(
        0, // selector telling to use the std range's begin()/end()
        make_std_range(mo_range),
        sort_proc
    );
}
#endif

LAGOON_NAMESPACE_END

#endif //include guard