diff --git a/sprout/algorithm/cxx14.hpp b/sprout/algorithm/cxx14.hpp
index 467fdd15..8a12fb0e 100644
--- a/sprout/algorithm/cxx14.hpp
+++ b/sprout/algorithm/cxx14.hpp
@@ -48,16 +48,16 @@
 #include <sprout/algorithm/cxx14/nth_element.hpp>
 #include <sprout/algorithm/cxx14/merge.hpp>
 #include <sprout/algorithm/cxx14/inplace_merge.hpp>
-//#include <sprout/algorithm/cxx14/set_union.hpp>
-//#include <sprout/algorithm/cxx14/set_intersection.hpp>
-//#include <sprout/algorithm/cxx14/set_difference.hpp>
-//#include <sprout/algorithm/cxx14/set_symmetric_difference.hpp>
-//#include <sprout/algorithm/cxx14/push_heap.hpp>
-//#include <sprout/algorithm/cxx14/pop_heap.hpp>
-//#include <sprout/algorithm/cxx14/make_heap.hpp>
-//#include <sprout/algorithm/cxx14/sort_heap.hpp>
-//#include <sprout/algorithm/cxx14/next_permutation.hpp>
-//#include <sprout/algorithm/cxx14/prev_permutation.hpp>
+#include <sprout/algorithm/cxx14/set_union.hpp>
+#include <sprout/algorithm/cxx14/set_intersection.hpp>
+#include <sprout/algorithm/cxx14/set_difference.hpp>
+#include <sprout/algorithm/cxx14/set_symmetric_difference.hpp>
+#include <sprout/algorithm/cxx14/push_heap.hpp>
+#include <sprout/algorithm/cxx14/pop_heap.hpp>
+#include <sprout/algorithm/cxx14/make_heap.hpp>
+#include <sprout/algorithm/cxx14/sort_heap.hpp>
+#include <sprout/algorithm/cxx14/next_permutation.hpp>
+#include <sprout/algorithm/cxx14/prev_permutation.hpp>
 #include <sprout/algorithm/cxx14/sample.hpp>
 #include <sprout/algorithm/cxx14/copy_while.hpp>
 #include <sprout/algorithm/cxx14/copy_until.hpp>
diff --git a/sprout/algorithm/cxx14/detail/heap_tool.hpp b/sprout/algorithm/cxx14/detail/heap_tool.hpp
new file mode 100644
index 00000000..d31dc293
--- /dev/null
+++ b/sprout/algorithm/cxx14/detail/heap_tool.hpp
@@ -0,0 +1,85 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_DETAIL_HEAP_TOOL_HPP
+#define SPROUT_ALGORITHM_CXX14_DETAIL_HEAP_TOOL_HPP
+
+#include <iterator>
+#include <sprout/config.hpp>
+#include <sprout/utility/move.hpp>
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename RandomAccessIterator>
+		inline SPROUT_CXX14_CONSTEXPR void
+		push_heap_front(
+			RandomAccessIterator first, RandomAccessIterator, Compare comp,
+			typename std::iterator_traits<RandomAccessIterator>::difference_type len
+			)
+		{
+			typedef typename std::iterator_traits<RandomAccessIterator>::difference_type difference_type;
+			typedef typename std::iterator_traits<RandomAccessIterator>::value_type value_type;
+			if (len > 1) {
+				difference_type p = 0;
+				RandomAccessIterator pp = first;
+				difference_type c = 2;
+				RandomAccessIterator cp = first + c;
+				if (c == len || comp(*cp, *(cp - 1))) {
+					--c;
+					--cp;
+				}
+				if (comp(*pp, *cp)) {
+					value_type t(sprout::move(*pp));
+					do {
+						*pp = sprout::move(*cp);
+						pp = cp;
+						p = c;
+						c = (p + 1) * 2;
+						if (c > len) {
+							break;
+						}
+						cp = first + c;
+						if (c == len || comp(*cp, *(cp - 1))) {
+							--c;
+							--cp;
+						}
+					} while (comp(t, *cp));
+					*pp = sprout::move(t);
+				}
+			}
+		}
+		template<typename Compare, typename RandomAccessIterator>
+		inline SPROUT_CXX14_CONSTEXPR void
+		push_heap_back(
+			RandomAccessIterator first, RandomAccessIterator last, Compare comp,
+			typename std::iterator_traits<RandomAccessIterator>::difference_type len
+			)
+		{
+			typedef typename std::iterator_traits<RandomAccessIterator>::difference_type difference_type;
+			typedef typename std::iterator_traits<RandomAccessIterator>::value_type value_type;
+			if (len > 1) {
+				len = (len - 2) / 2;
+				RandomAccessIterator ptr = first + len;
+				if (comp(*ptr, *--last)) {
+					value_type t(sprout::move(*last));
+					do {
+						*last = sprout::move(*ptr);
+						last = ptr;
+						if (len == 0) {
+							break;
+						}
+						len = (len - 1) / 2;
+						ptr = first + len;
+					} while (comp(*ptr, t));
+					*last = sprout::move(t);
+				}
+			}
+		}
+	}	// namespace detail
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_DETAIL_HEAP_TOOL_HPP
diff --git a/sprout/algorithm/cxx14/make_heap.hpp b/sprout/algorithm/cxx14/make_heap.hpp
new file mode 100644
index 00000000..42536583
--- /dev/null
+++ b/sprout/algorithm/cxx14/make_heap.hpp
@@ -0,0 +1,53 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_MAKE_HEAP_HPP
+#define SPROUT_ALGORITHM_CXX14_MAKE_HEAP_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/detail/heap_tool.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename RandomAccessIterator>
+		inline SPROUT_CXX14_CONSTEXPR void
+		make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+			typedef typename std::iterator_traits<RandomAccessIterator>::difference_type difference_type;
+			difference_type len = last - first;
+			if (len > 1) {
+				last = first;
+				++last;
+				for (difference_type i = 1; i < len; ++i) {
+					sprout::detail::push_heap_back<Compare>(first, ++last, comp, i);
+				}
+			}
+		}
+	}	// namespace detail
+	//
+	// 25.4.6.3 make_heap
+	//
+	template<typename RandomAccessIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR void
+	make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		sprout::detail::make_heap<compare_ref>(first, last, comp);
+	}
+
+	template<typename RandomAccessIterator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	make_heap(RandomAccessIterator first, RandomAccessIterator last) {
+		sprout::make_heap(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_MAKE_HEAP_HPP
diff --git a/sprout/algorithm/cxx14/next_permutation.hpp b/sprout/algorithm/cxx14/next_permutation.hpp
new file mode 100644
index 00000000..2c9d9d8f
--- /dev/null
+++ b/sprout/algorithm/cxx14/next_permutation.hpp
@@ -0,0 +1,64 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_NEXT_PERMUTATION_HPP
+#define SPROUT_ALGORITHM_CXX14_NEXT_PERMUTATION_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/reverse.hpp>
+#include <sprout/utility/swap.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename BidirectionalIterator>
+		inline SPROUT_CXX14_CONSTEXPR bool
+		next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
+			BidirectionalIterator i = last;
+			if (first == last || first == --i) {
+				return false;
+			}
+			while (true) {
+				BidirectionalIterator ip1 = i;
+				if (comp(*--i, *ip1)) {
+					BidirectionalIterator j = last;
+					while (!comp(*i, *--j))
+						;
+					sprout::swap(*i, *j);
+					sprout::reverse(ip1, last);
+					return true;
+				}
+				if (i == first) {
+					sprout::reverse(first, last);
+					return false;
+				}
+			}
+		}
+	}	// namespace detail
+	//
+	// 25.4.9 Permutation generators
+	//
+	template<typename BidirectionalIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR bool
+	next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		return sprout::detail::next_permutation<compare_ref>(first, last, comp);
+	}
+
+	template<typename BidirectionalIterator>
+	inline SPROUT_CXX14_CONSTEXPR bool
+	next_permutation(BidirectionalIterator first, BidirectionalIterator last) {
+		return sprout::next_permutation(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<BidirectionalIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_NEXT_PERMUTATION_HPP
diff --git a/sprout/algorithm/cxx14/pop_heap.hpp b/sprout/algorithm/cxx14/pop_heap.hpp
new file mode 100644
index 00000000..0332eb56
--- /dev/null
+++ b/sprout/algorithm/cxx14/pop_heap.hpp
@@ -0,0 +1,53 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_POP_HEAP_HPP
+#define SPROUT_ALGORITHM_CXX14_POP_HEAP_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/detail/heap_tool.hpp>
+#include <sprout/utility/swap.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename RandomAccessIterator>
+		inline SPROUT_CXX14_CONSTEXPR void
+		pop_heap(
+			RandomAccessIterator first, RandomAccessIterator last, Compare comp,
+			typename std::iterator_traits<RandomAccessIterator>::difference_type len
+			)
+		{
+			if (len > 1) {
+				sprout::swap(*first, *--last);
+				sprout::detail::push_heap_front<Compare>(first, last, comp, len - 1);
+			}
+		}
+	}	// namespace detail
+	//
+	// 25.4.6.2 pop_heap
+	//
+	template<typename RandomAccessIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR void
+	pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		sprout::detail::pop_heap<compare_ref>(first, last, comp, last - first);
+	}
+
+	template<typename RandomAccessIterator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	pop_heap(RandomAccessIterator first, RandomAccessIterator last) {
+		sprout::pop_heap(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_POP_HEAP_HPP
diff --git a/sprout/algorithm/cxx14/prev_permutation.hpp b/sprout/algorithm/cxx14/prev_permutation.hpp
new file mode 100644
index 00000000..f4c462f5
--- /dev/null
+++ b/sprout/algorithm/cxx14/prev_permutation.hpp
@@ -0,0 +1,64 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP
+#define SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/reverse.hpp>
+#include <sprout/utility/swap.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename BidirectionalIterator>
+		inline SPROUT_CXX14_CONSTEXPR bool
+		prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
+			BidirectionalIterator i = last;
+			if (first == last || first == --i) {
+				return false;
+			}
+			while (true) {
+				BidirectionalIterator ip1 = i;
+				if (comp(*ip1, *--i)) {
+					BidirectionalIterator j = last;
+					while (!comp(*--j, *i))
+						;
+					sprout::swap(*i, *j);
+					sprout::reverse(ip1, last);
+					return true;
+				}
+				if (i == first) {
+					sprout::reverse(first, last);
+					return false;
+				}
+			}
+		}
+	}	// namespace detail
+	//
+	// 25.4.9 Permutation generators
+	//
+	template<typename BidirectionalIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR bool
+	prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		return sprout::detail::prev_permutation<compare_ref>(first, last, comp);
+	}
+
+	template<typename BidirectionalIterator>
+	inline SPROUT_CXX14_CONSTEXPR bool
+	prev_permutation(BidirectionalIterator first, BidirectionalIterator last) {
+		return sprout::prev_permutation(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<BidirectionalIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP
diff --git a/sprout/algorithm/cxx14/push_heap.hpp b/sprout/algorithm/cxx14/push_heap.hpp
new file mode 100644
index 00000000..b7561b13
--- /dev/null
+++ b/sprout/algorithm/cxx14/push_heap.hpp
@@ -0,0 +1,38 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_PUSH_HEAP_HPP
+#define SPROUT_ALGORITHM_CXX14_PUSH_HEAP_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/detail/heap_tool.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	//
+	// 25.4.6.1 push_heap
+	//
+	template<typename RandomAccessIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR void
+	push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		sprout::detail::push_heap_back<compare_ref>(first, last, comp, last - first);
+	}
+
+	template<typename RandomAccessIterator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	push_heap(RandomAccessIterator first, RandomAccessIterator last) {
+		sprout::push_heap(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_PUSH_HEAP_HPP
diff --git a/sprout/algorithm/cxx14/set_difference.hpp b/sprout/algorithm/cxx14/set_difference.hpp
new file mode 100644
index 00000000..1a0fde67
--- /dev/null
+++ b/sprout/algorithm/cxx14/set_difference.hpp
@@ -0,0 +1,55 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_SET_DIFFERENCE_HPP
+#define SPROUT_ALGORITHM_CXX14_SET_DIFFERENCE_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/algorithm/cxx14/copy.hpp>
+#include <sprout/functional/less.hpp>
+
+namespace sprout {
+	//
+	// 25.4.5.4 set_difference
+	//
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator, typename Compare,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp) {
+		while (first1 != last1 && first2 != last2) {
+			if (comp(*first1, *first2)) {
+				*result = *first1;
+				++first1;
+				++result;
+			} else if (comp(*first2, *first1)) {
+				++first2;
+			} else {
+				++first1;
+				++first2;
+			}
+		}
+		return sprout::copy(first1, last1, result);
+	}
+
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result) {
+		return sprout::set_difference(
+			first1, last1, first2, last2, result,
+			sprout::less<>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_SET_DIFFERENCE_HPP
diff --git a/sprout/algorithm/cxx14/set_intersection.hpp b/sprout/algorithm/cxx14/set_intersection.hpp
new file mode 100644
index 00000000..28353d06
--- /dev/null
+++ b/sprout/algorithm/cxx14/set_intersection.hpp
@@ -0,0 +1,54 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_SET_INTERSECTION_HPP
+#define SPROUT_ALGORITHM_CXX14_SET_INTERSECTION_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/functional/less.hpp>
+
+namespace sprout {
+	//
+	// 25.4.5.3 set_intersection
+	//
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator, typename Compare,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_intersection(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp) {
+		while (first1 != last1 && first2 != last2) {
+			if (comp(*first1, *first2)) {
+				++first1;
+			} else if (comp(*first2, *first1)) {
+				++first2;
+			} else {
+				*result = *first1;
+				++first1;
+				++first2;
+				++result;
+			}
+		}
+		return result;
+	}
+
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_intersection(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result) {
+		return sprout::set_intersection(
+			first1, last1, first2, last2, result,
+			sprout::less<>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_SET_INTERSECTION_HPP
diff --git a/sprout/algorithm/cxx14/set_symmetric_difference.hpp b/sprout/algorithm/cxx14/set_symmetric_difference.hpp
new file mode 100644
index 00000000..129a33e8
--- /dev/null
+++ b/sprout/algorithm/cxx14/set_symmetric_difference.hpp
@@ -0,0 +1,62 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_SET_SYMMETRIC_DIFFERENCE_HPP
+#define SPROUT_ALGORITHM_CXX14_SET_SYMMETRIC_DIFFERENCE_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/algorithm/cxx14/copy.hpp>
+#include <sprout/functional/less.hpp>
+
+namespace sprout {
+	//
+	// 25.4.5.5 set_symmetric_difference
+	//
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator, typename Compare,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp) {
+		while (true) {
+			if (first1 == last1) {
+				return std::copy(first2, last2, result);
+			}
+			if (first2 == last2) {
+				return std::copy(first1, last1, result);
+			}
+			if (comp(*first1, *first2)) {
+				*result = *first1;
+				++first1;
+				++result;
+			} else if (comp(*first2, *first1)) {
+				*result = *first2;
+				++first2;
+				++result;
+			} else {
+				++first1;
+				++first2;
+			}
+		}
+	}
+
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result) {
+		return sprout::set_symmetric_difference(
+			first1, last1, first2, last2, result,
+			sprout::less<>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_SET_SYMMETRIC_DIFFERENCE_HPP
diff --git a/sprout/algorithm/cxx14/set_union.hpp b/sprout/algorithm/cxx14/set_union.hpp
new file mode 100644
index 00000000..c571abb7
--- /dev/null
+++ b/sprout/algorithm/cxx14/set_union.hpp
@@ -0,0 +1,62 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_SET_UNION_HPP
+#define SPROUT_ALGORITHM_CXX14_SET_UNION_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/algorithm/cxx14/copy.hpp>
+#include <sprout/functional/less.hpp>
+
+namespace sprout {
+	//
+	// 25.4.5.2 set_union
+	//
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator, typename Compare,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_union(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp) {
+		while (true) {
+			if (first1 == last1) {
+				return std::copy(first2, last2, result);
+			}
+			if (first2 == last2) {
+				return std::copy(first1, last1, result);
+			}
+			if (comp(*first1, *first2)) {
+				*result = *first1;
+				++first1;
+			} else if (comp(*first2, *first1)) {
+				*result = *first2;
+				++first2;
+			} else {
+				*result = *first1;
+				++first1;
+				++first2;
+			}
+			++result;
+		}
+	}
+
+	template<
+		typename InputIterator1, typename InputIterator2, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_iterator_outputable<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	set_union(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result) {
+		return sprout::set_union(
+			first1, last1, first2, last2, result,
+			sprout::less<>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_SET_UNION_HPP
diff --git a/sprout/algorithm/cxx14/sort.hpp b/sprout/algorithm/cxx14/sort.hpp
index 2d10f0af..8add0334 100644
--- a/sprout/algorithm/cxx14/sort.hpp
+++ b/sprout/algorithm/cxx14/sort.hpp
@@ -16,7 +16,6 @@
 #include <sprout/utility/swap.hpp>
 #include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
 
-
 namespace sprout {
 	namespace detail {
 		template<typename Compare, typename RandomAccessIterator>
diff --git a/sprout/algorithm/cxx14/sort_heap.hpp b/sprout/algorithm/cxx14/sort_heap.hpp
new file mode 100644
index 00000000..03463822
--- /dev/null
+++ b/sprout/algorithm/cxx14/sort_heap.hpp
@@ -0,0 +1,49 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_ALGORITHM_CXX14_SORT_HEAP_HPP
+#define SPROUT_ALGORITHM_CXX14_SORT_HEAP_HPP
+
+#include <iterator>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/algorithm/cxx14/pop_heap.hpp>
+#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace detail {
+		template<typename Compare, typename RandomAccessIterator>
+		inline SPROUT_CXX14_CONSTEXPR void
+		sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+			typedef typename std::iterator_traits<RandomAccessIterator>::difference_type difference_type;
+			difference_type len = last - first;
+			for (difference_type len = last - first; len > 1; --last, --len) {
+				sprout::detail::pop_heap<Compare>(first, last, comp, len);
+			}
+		}
+	}	// namespace detail
+	//
+	// 25.4.6.4 sort_heap
+	//
+	template<typename RandomAccessIterator, typename Compare>
+	inline SPROUT_CXX14_CONSTEXPR void
+	sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
+		typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
+		sprout::detail::sort_heap<compare_ref>(first, last, comp);
+	}
+
+	template<typename RandomAccessIterator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	sort_heap(RandomAccessIterator first, RandomAccessIterator last) {
+		sprout::sort_heap(
+			first, last,
+			NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_CXX14_SORT_HEAP_HPP