std::iostream error condition checks fixes.
HalfData declaration.
sorters::HalfSplitSorter partial implementation.
sorters::HalfSplitSorter refactoring + memory usage bug fix.
sorters::HalfSplitSorter: will not create empty files.
sorters::HalfSplitSorter::sort()#split: explicit flush().
sorters::HalfSplitSorter::sort()#count refactoring.
sorters::HalfSplitSorter bug fix.
detail::MemoryMap zero-size map bug fix.
sorters::SplitMergeSorter draft.
detail::Queue move semantics support + alternative pop() declaration.
sorters::SplitMergeSorter pipeline implementation.