diff --git a/sprout/array/array.hpp b/sprout/array/array.hpp
index 2a8ecb6e..587895d6 100644
--- a/sprout/array/array.hpp
+++ b/sprout/array/array.hpp
@@ -216,6 +216,46 @@ namespace sprout {
 				throw std::out_of_range("array<>: index out of range");
 			}
 		}
+
+#if SPROUT_USE_INDEX_ITERATOR_IMPLEMENTATION
+		SPROUT_CXX14_CONSTEXPR iterator nth(size_type i) {
+			return i < size()
+				? iterator(*this, i)
+				: (throw std::out_of_range("array<>: index out of range"), iterator())
+				;
+		}
+		SPROUT_CONSTEXPR const_iterator nth(size_type i) const {
+			return i < size()
+				? const_iterator(*this, i)
+				: (throw std::out_of_range("array<>: index out of range"), const_iterator())
+				;
+		}
+		SPROUT_CONSTEXPR size_type index_of(iterator p) const SPROUT_NOEXCEPT {
+			return p.index();
+		}
+		SPROUT_CONSTEXPR size_type index_of(const_iterator p) const SPROUT_NOEXCEPT {
+			return p.index();
+		}
+#else
+		SPROUT_CXX14_CONSTEXPR iterator nth(size_type i) {
+			return i < size()
+				? iterator(elems) + i
+				: (throw std::out_of_range("array<>: index out of range"), iterator())
+				;
+		}
+		SPROUT_CONSTEXPR const_iterator nth(size_type i) const {
+			return i < size()
+				? const_iterator(elems) + i
+				: (throw std::out_of_range("array<>: index out of range"), const_iterator())
+				;
+		}
+		SPROUT_CONSTEXPR size_type index_of(iterator p) const SPROUT_NOEXCEPT {
+			return sprout::distance(begin(), p);
+		}
+		SPROUT_CONSTEXPR size_type index_of(const_iterator p) const SPROUT_NOEXCEPT {
+			return sprout::distance(begin(), p);
+		}
+#endif
 	};
 	template<typename T, std::size_t N>
 	SPROUT_CONSTEXPR_OR_CONST typename sprout::array<T, N>::size_type sprout::array<T, N>::static_size;
diff --git a/sprout/string/string.hpp b/sprout/string/string.hpp
index d4195f3f..d9e0f216 100644
--- a/sprout/string/string.hpp
+++ b/sprout/string/string.hpp
@@ -933,6 +933,46 @@ namespace sprout {
 				;
 		}
 #endif
+
+#if SPROUT_USE_INDEX_ITERATOR_IMPLEMENTATION
+		SPROUT_CXX14_CONSTEXPR iterator nth(size_type i) {
+			return i < size()
+				? iterator(*this, i)
+				: (throw std::out_of_range("basic_string<>: index out of range"), iterator())
+				;
+		}
+		SPROUT_CONSTEXPR const_iterator nth(size_type i) const {
+			return i < size()
+				? const_iterator(*this, i)
+				: (throw std::out_of_range("basic_string<>: index out of range"), const_iterator())
+				;
+		}
+		SPROUT_CONSTEXPR size_type index_of(iterator p) const SPROUT_NOEXCEPT {
+			return p.index();
+		}
+		SPROUT_CONSTEXPR size_type index_of(const_iterator p) const SPROUT_NOEXCEPT {
+			return p.index();
+		}
+#else
+		SPROUT_CXX14_CONSTEXPR iterator nth(size_type i) {
+			return i < size()
+				? data() + i
+				: (throw std::out_of_range("basic_string<>: index out of range"), iterator())
+				;
+		}
+		SPROUT_CONSTEXPR const_iterator nth(size_type i) const {
+			return i < size()
+				? data() + i
+				: (throw std::out_of_range("basic_string<>: index out of range"), const_iterator())
+				;
+		}
+		SPROUT_CONSTEXPR size_type index_of(iterator p) const SPROUT_NOEXCEPT {
+			return sprout::distance(begin(), p);
+		}
+		SPROUT_CONSTEXPR size_type index_of(const_iterator p) const SPROUT_NOEXCEPT {
+			return sprout::distance(begin(), p);
+		}
+#endif
 	};
 	template<typename T, std::size_t N, typename Traits>
 	SPROUT_CONSTEXPR_OR_CONST typename sprout::basic_string<T, N, Traits>::size_type sprout::basic_string<T, N, Traits>::npos;
diff --git a/sprout/sub_array/sub_array.hpp b/sprout/sub_array/sub_array.hpp
index dd9fb73c..316a5e7d 100644
--- a/sprout/sub_array/sub_array.hpp
+++ b/sprout/sub_array/sub_array.hpp
@@ -415,6 +415,25 @@ namespace sprout {
 		SPROUT_CONSTEXPR difference_type from_end() const {
 			return to_last_ - sprout::size(get_array());
 		}
+
+		SPROUT_CXX14_CONSTEXPR iterator nth(size_type i) {
+			return i < size()
+				? sprout::next(begin(), i)
+				: (throw std::out_of_range("sub_array<>: index out of range"), iterator())
+				;
+		}
+		SPROUT_CONSTEXPR const_iterator nth(size_type i) const {
+			return i < size()
+				? sprout::next(begin(), i)
+				: (throw std::out_of_range("array<>: index out of range"), const_iterator())
+				;
+		}
+		SPROUT_CXX14_CONSTEXPR size_type index_of(iterator p) {
+			return sprout::distance(begin(), p);
+		}
+		SPROUT_CONSTEXPR size_type index_of(const_iterator p) const {
+			return sprout::distance(begin(), p);
+		}
 	};
 	template<typename Container>
 	SPROUT_CONSTEXPR_OR_CONST typename sprout::sub_array<Container>::size_type sprout::sub_array<Container>::enumerable_size;