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Function template string_sort

boost::sort::spreadsort::string_sort — String sort algorithm using range, wraps using default of unsigned char.


// In header: <boost/sort/spreadsort/string_sort.hpp>

template<typename Range, typename Get_char, typename Get_length, 
         typename Compare> 
  void string_sort(Range & range, Get_char get_character, Get_length length, 
                   Compare comp);


(All variants fall back to boost::sort::pdqsort if the data size is too small, < detail::min_sort_size).

string_sort is a fast templated in-place hybrid radix/comparison algorithm, which in testing tends to be roughly 50% to 2X faster than std::sort for large tests (>=100kB).

 Worst-case performance is O(N * (lg(range)/s + s)) , so string_sort is asymptotically faster than pure comparison-based algorithms.

Some performance plots of runtime vs. n and log(range) are provided:

[Warning] Warning

Throwing an exception may cause data loss. This will also throw if a small vector resize throws, in which case there will be no data loss.

[Warning] Warning

Invalid arguments cause undefined behaviour.

[Note] Note

spreadsort function provides a wrapper that calls the fastest sorting algorithm available for a data type, enabling faster generic-programming.

The lesser of O(N*log(N)) comparisons and O(N*log(K/S + S)) operations worst-case, where:

* N is last - first,

* K is the log of the range in bits (32 for 32-bit integers using their full range),

* S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size).



A binary functor that returns whether the first element passed to it should go before the second in order.


Bracket functor equivalent to operator[], taking a number corresponding to the character offset.


Functor to get the length of the string in characters.


Range [first, last) for sorting.


[first, last) is a valid range.


The elements in the range [first, last) are sorted in ascending order.




std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves), the right shift, subtraction of right-shifted elements, functors, or any operations on iterators throw.