add algorithm::partition

octa/algorithm.h

@@ -10,6 +10,18 @@
 #include "octa/range.h"
 
 namespace octa {
+    template<typename R, typename U>
+    R partition(R range, U pred) {
+        R ret = range;
+        for (; !range.empty(); range.pop_first()) {
+            if (pred(range.first())) {
+                swap(range.first(), ret.first());
+                ret.pop_first();
+            }
+        }
+        return ret;
+    }
+
     template<typename R, typename C>
     void insertion_sort(R range, C compare) {
         size_t rlen = range.length();
@@ -28,7 +40,6 @@ namespace octa {
         insertion_sort(range, Less<typename RangeTraits<R>::value>());
     }
 
-
     template<typename R, typename C>
     void sort(R range, C compare) {
         insertion_sort(range, compare);

octa/utility.h

@@ -38,17 +38,6 @@ namespace std {
 namespace octa {
     template<typename T> using InitializerList = std::initializer_list<T>;
 
-    template<typename T> void swap(T &a, T &b) {
-        T c(move(a));
-        a = move(b);
-        b = move(c);
-    }
-    template<typename T, size_t N> void swap(T (&a)[N], T (&b)[N]) {
-        for (size_t i = 0; i < N; ++i) {
-            swap(a[i], b[i]);
-        }
-    }
-
     /* aliased in traits.h later */
     namespace internal {
         template<typename T> struct RemoveReference      { typedef T type; };
@@ -153,6 +142,17 @@ namespace octa {
     internal::MemFn<R, T> mem_fn(R T:: *ptr) {
         return internal::MemFn<R, T>(ptr);
     }
+
+    template<typename T> void swap(T &a, T &b) {
+        T c(move(a));
+        a = move(b);
+        b = move(c);
+    }
+    template<typename T, size_t N> void swap(T (&a)[N], T (&b)[N]) {
+        for (size_t i = 0; i < N; ++i) {
+            swap(a[i], b[i]);
+        }
+    }
 }
 
 #endif