Add sort

Author: d-frey

README.md

@@ -395,13 +395,34 @@ Examples:
 * `at_index<0,bool,int,void,char*>` ➙ `bool`
 * `at_index<2,bool,int,void,char*>` ➙ `void`
 
+#### Header `tao/seq/sort.hpp`
+
+Sort a sequence according to a given predicate.
+
+* `sort_t< typename OP, typename T, T... Ns >`
+* `sort_t< typename OP, typename S >`
+
+Examples:
+
+* Given a predicate `less`:
+
+    struct less
+    {
+       template< typename T, T A, T B >
+       using apply = std::integral_constant< bool, ( A < B ) >;
+    };
+
+* `sort_t<less,int,7,-2,3,0,4>` ➙ `integer_sequence<int,-2,0,3,4,7>`
+* `using S = index_sequence<39,4,2,10>`
+* `sort_t<less,S>` ➙ `index_sequence<2,4,10,39>`
+
 ## Changelog
 
 ### 1.1.0
 
 **Not yet released**
 
-* Added `prod`, `multiply`, `difference`, `index_of_seq`, and `permutate`.
+* Added `prod`, `multiply`, `difference`, `index_of_seq`, `permutate`, and `sort`.
 
 ### 1.0.2
 

include/tao/seq/sort.hpp

@@ -0,0 +1,71 @@
+// Copyright (c) 2019 Daniel Frey
+// Please see LICENSE for license or visit https://github.com/taocpp/sequences/
+
+#ifndef TAO_SEQ_SORT_HPP
+#define TAO_SEQ_SORT_HPP
+
+#include <type_traits>
+
+#include "integer_sequence.hpp"
+#include "sequence_helper.hpp"
+
+namespace tao
+{
+   namespace seq
+   {
+      namespace impl
+      {
+         template< typename OP, typename T, T V, typename S, typename R >
+         struct insert;
+
+         template< typename OP, typename T, T V, T... Rs >
+         struct insert< OP, T, V, integer_sequence< T >, integer_sequence< T, Rs... > >
+         {
+            using type = integer_sequence< T, Rs..., V >;
+         };
+
+         template< typename OP, typename T, T V, T N, T... Ns, T... Rs >
+         struct insert< OP, T, V, integer_sequence< T, N, Ns... >, integer_sequence< T, Rs... > >
+         {
+            using type = typename conditional< OP::template apply< T, V, N >::value >::template type<
+               integer_sequence< T, Rs..., V, N, Ns... >,
+               typename insert< OP, T, V, integer_sequence< T, Ns... >, integer_sequence< T, Rs..., N > >::type >;
+         };
+
+         template< typename OP, typename Sorted, typename Unsorted >
+         struct sort;
+
+         template< typename OP, typename T, T... Ns >
+         struct sort< OP, integer_sequence< T, Ns... >, integer_sequence< T > >
+         {
+            using type = integer_sequence< T, Ns... >;
+         };
+
+         template< typename OP, typename T, T... Ns, T V, T... Rs >
+         struct sort< OP, integer_sequence< T, Ns... >, integer_sequence< T, V, Rs... > >
+            : sort< OP, typename insert< OP, T, V, integer_sequence< T, Ns... >, integer_sequence< T > >::type, integer_sequence< T, Rs... > >
+         {
+         };
+
+      }  // namespace impl
+
+      template< typename OP, typename T, T... Ns >
+      struct sort
+         : impl::sort< OP, integer_sequence< T >, integer_sequence< T, Ns... > >
+      {
+      };
+
+      template< typename OP, typename T, T... Ns >
+      struct sort< OP, integer_sequence< T, Ns... > >
+         : sort< OP, T, Ns... >
+      {
+      };
+
+      template< typename OP, typename S >
+      using sort_t = typename sort< OP, S >::type;
+
+   }  // namespace seq
+
+}  // namespace tao
+
+#endif

src/test/seq/CMakeLists.txt

@@ -27,6 +27,7 @@ set (test_sources
   prod.cpp
   scale.cpp
   select.cpp
+  sort.cpp
   sum.cpp
   tail.cpp
   tester.cpp

src/test/seq/sort.cpp

@@ -0,0 +1,31 @@
+// Copyright (c) 2019 Daniel Frey
+// Please see LICENSE for license or visit https://github.com/taocpp/sequences/
+
+#include <tao/seq/make_integer_sequence.hpp>
+#include <tao/seq/sort.hpp>
+
+#include <type_traits>
+
+struct less
+{
+   template< typename T, T A, T B >
+   using apply = std::integral_constant< bool, ( A < B ) >;
+};
+
+int main()
+{
+   using namespace tao::seq;
+
+   static_assert( std::is_same< sort_t< less, index_sequence<> >, index_sequence<> >::value, "oops" );
+
+   static_assert( std::is_same< sort_t< less, index_sequence< 42 > >, index_sequence< 42 > >::value, "oops" );
+
+   using S = integer_sequence< int, 7, -2, 3, 0, 4 >;
+   static_assert( std::is_same< sort_t< less, S >, integer_sequence< int, -2, 0, 3, 4, 7 > >::value, "oops" );
+
+   using I = index_sequence< 39, 2, 4, 10 >;
+   static_assert( std::is_same< sort_t< less, I >, index_sequence< 2, 4, 10, 39 > >::value, "oops" );
+
+   using L = index_sequence< 54, 12, 45, 20, 91, 99, 16, 73, 62, 19, 30, 34, 67, 49, 18, 11, 25, 22, 86, 87, 44, 2, 21, 79, 15, 41, 55, 84, 48, 75, 23, 68, 88, 94, 40, 72, 71, 69, 57, 35, 90, 4, 56, 6, 10, 80, 64, 50, 28, 1, 52, 27, 5, 0, 78, 32, 7, 24, 14, 13, 65, 70, 83, 81, 51, 33, 37, 66, 47, 29, 42, 93, 89, 9, 46, 77, 58, 60, 3, 76, 92, 63, 39, 96, 53, 26, 31, 17, 38, 85, 98, 59, 43, 97, 95, 36, 74, 61, 8, 82 >;
+   static_assert( std::is_same< sort_t< less, L >, make_index_sequence< 100 > >::value, "oops" );
+}