diff --git a/data.hpp b/data.hpp
index 8f59234..cdf0e33 100644
--- a/data.hpp
+++ b/data.hpp
@@ -106,8 +106,8 @@ namespace asp {
 	};
 
 	template<typename T>
-	constexpr T& max(const Array<T>& a) noexcept {
-		T& max_el = a[0];
+	constexpr T max(const Array<T>& a) noexcept {
+		T max_el = a[0];
 		for (size_t i = 1; i < a.length; ++i)
 			if (a[i] > max_el)
 				max_el = a[i];
@@ -138,26 +138,19 @@ namespace asp {
 
 	inline Array<size_t> range(const size_t& n) noexcept {
 		Array<size_t> a(n);
-		return map(a, [](const size_t& i, const size_t&) -> const size_t& {
+		return map(a, [](const size_t i, const size_t) -> size_t {
 			return i;
 		});
 	}
 
 	template<typename T>
-	constexpr void swap(T* const a, T* const b) noexcept {
-		const T temp = *a;
-		*a = *b;
-		*b = temp;
-	}
-
-	template<typename T>
-	constexpr void bubble_sort(const Array<T>& a) noexcept {
+	constexpr void bubble_sort(Array<T>& a) noexcept {
 		size_t j = 0;
 		for (size_t i = 0; i < a.length; ++i) {
 			bool swapped = false;
 			for (j = i + 1; j < a.length; ++j)
 				if (a[i] > a[j]) {
-					swap(&a[i], &a[j]);
+					std::swap(a[i], a[j]);
 					swapped = true;
 				}
 			if (!swapped)
@@ -166,15 +159,15 @@ namespace asp {
 	}
 
 	template<typename T>
-	Array<size_t> bubble_sort_arg(const Array<T>& a) noexcept {
+	inline Array<size_t> bubble_sort_arg(Array<T>& a) noexcept {
 		Array<size_t> indices = range(a.length);
 		size_t j;
 		for (size_t i = 0; i < a.length; ++i) {
 			bool swapped = false;
 			for (j = i + 1; j < a.length; ++j)
 				if (a[i] > a[j]) {
-					swap(&indices[i], &indices[j]);
-					swap(&a[i], &a[j]);
+					std::swap(indices[i], indices[j]);
+					std::swap(a[i], a[j]);
 					swapped = true;
 				}
 			if (!swapped)
@@ -184,17 +177,17 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr size_t qs_partition(const Array<T>& a, const size_t& l, const size_t& h) noexcept {
+	constexpr size_t qs_partition(Array<T>& a, const size_t& l, const size_t& h) noexcept {
 		size_t i = l - 1;
 		for (size_t j = l; j <= h; ++j)
 			if (a[j] < a[h])
-				swap(&a[++i], &a[j]);
-		swap(&a[++i], &a[h]);
+				std::swap(a[++i], a[j]);
+		std::swap(a[++i], a[h]);
 		return i;
 	}
 
 	template<typename T>
-	constexpr void quicksort(const Array<T>& a, const size_t& l, const size_t& h) noexcept {
+	constexpr void quicksort(Array<T>& a, const size_t& l, const size_t& h) noexcept {
 		if (l >= h)
 			return;
 
@@ -205,12 +198,12 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr void quicksort(const Array<T>& a) noexcept {
+	constexpr void quicksort(Array<T>& a) noexcept {
 		quicksort(a, 0, a.length - 1);
 	}
 
 	template<typename T>
-	constexpr void quicksort_iter(const Array<T>& a, const size_t& l, const size_t& h) noexcept {
+	constexpr void quicksort_iter(Array<T>& a, const size_t& l, const size_t& h) noexcept {
 		// Create an auxiliary stack
 
 		const size_t total = h - l + 1;
@@ -253,25 +246,25 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr void quicksort_iter(const Array<T>& a) noexcept {
+	constexpr void quicksort_iter(Array<T>& a) noexcept {
 		quicksort_iter(a, 0, a.length - 1);
 	}
 
 	template<typename T>
-	constexpr size_t qs_arg_partition(const Array<T>& a, const Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
+	constexpr size_t qs_arg_partition(Array<T>& a, Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
 		size_t i = l - 1;
 		for (size_t j = l; j <= h; ++j)
 			if (a[j] < a[h]){
-				swap(&a[++i], &a[j]);
-				swap(&indices[i], &indices[j]);
+				std::swap(a[++i], a[j]);
+				std::swap(indices[i], indices[j]);
 			}
-		swap(&indices[++i], &indices[h]);
-		swap(&a[i], &a[h]);
+		std::swap(indices[++i], indices[h]);
+		std::swap(a[i], a[h]);
 		return i;
 	}
 
 	template<typename T>
-	constexpr void quicksort_arg(const Array<T>& a, const Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
+	constexpr void quicksort_arg(Array<T>& a, Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
 		if (l >= h)
 			return;
 
@@ -282,19 +275,19 @@ namespace asp {
 	}
 
 	template<typename T>
-	Array<size_t> quicksort_arg(const Array<T>& other, const size_t& l, const size_t& h) noexcept {
+	inline Array<size_t> quicksort_arg(Array<T>& other, const size_t& l, const size_t& h) noexcept {
 		Array<size_t> indices = range(other.length);
 		quicksort_arg(other, indices, l, h);
 		return indices;
 	}
 
 	template<typename T>
-	Array<size_t> quicksort_arg(const Array<T>& a) noexcept {
+	inline Array<size_t> quicksort_arg(Array<T>& a) noexcept {
 		return quicksort_arg(a, 0, a.length - 1);
 	}
 
 	template<typename T>
-	constexpr void quicksort_arg_iter(const Array<T>& a, const Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
+	inline void quicksort_arg_iter(Array<T>& a, Array<size_t>& indices, const size_t& l, const size_t& h) noexcept {
 		// Create an auxiliary stack
 		const size_t total = h - l + 1;
 		// push initial values of l and h to stack
@@ -334,7 +327,7 @@ namespace asp {
 	}
 
 	template<typename T>
-	Array<size_t> quicksort_arg_iter(const Array<T>& a) noexcept {
+	inline Array<size_t> quicksort_arg_iter(Array<T>& a) noexcept {
 		Array<size_t> indices = range(a.length);
 		quicksort_arg_iter(a, indices, 0, a.length - 1);
 		return indices;
@@ -363,7 +356,7 @@ namespace asp {
 	};
 
 	template<typename T>
-	constexpr void merge(const Array<T>& a, const size_t& l, const size_t& m, const size_t& r) noexcept {
+	constexpr void merge(Array<T>& a, const size_t& l, const size_t& m, const size_t& r) noexcept {
 
 		Array<T> left_arr(m - l + 1);
 		memcpy(&left_arr.data[0], &a[l], left_arr.length * sizeof(T));
@@ -384,7 +377,7 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr void mergesort(const Array<T>& a, const size_t& l, const size_t& r) noexcept {
+	constexpr void mergesort(Array<T>& a, const size_t& l, const size_t& r) noexcept {
 		if (l >= r)
 			return;
 
@@ -395,15 +388,15 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr void mergesort(const Array<T>& a) noexcept {
+	constexpr void mergesort(Array<T>& a) noexcept {
 		mergesort(a, 0, a.length - 1);
 	}
 
 	template<typename T>
-	Array<size_t> mergesort_arg(const Array<T>& a, const size_t& l, const size_t& r) noexcept {
+	inline Array<size_t> mergesort_arg(Array<T>& a) noexcept {
 
 		Array<ArgVal<T>> temp_vals(a.length);
-		map(temp_vals, [&a](const size_t& i, const ArgVal<T>&) -> const ArgVal<T> {
+		map(temp_vals, [&a](const size_t& i, const ArgVal<T>&) -> ArgVal<T> {
 			return ArgVal<T>(i, a[i]);
 		});
 
@@ -421,7 +414,7 @@ namespace asp {
 	}
 
 	template<typename T>
-	constexpr void insertion_sort(const Array<T>& a) noexcept {
+	constexpr void insertion_sort(Array<T>& a) noexcept {
 		size_t j = 0;
 		for(size_t i = 1; i < a.length; ++i) {
 			T key = a[i];
@@ -432,41 +425,18 @@ namespace asp {
 	}
 
 	template<typename T>
-	Array<size_t> insertion_argsort(const Array<T>& a) noexcept {
-		Array<size_t> indices = range(a.length);
-		size_t j = 0;
-		for(size_t i = 1; i < a.length; ++i){
-			for(j = i; j > 0 && a[indices[j - 1]] > a[indices[i]]; --j)
-				indices[j] = indices[j - 1];
-			indices[j] = i;
-		}
-		return indices;
-	}
-
-	template<typename T>
-	constexpr void counting_sort(const Array<T>& a) noexcept {
-		const size_t N = a.length;
-		const T M = max(a);
-
-		const T exp = 10;
-		const T d = 128;
-
-		Array<T> countArray(M);
-		memset(&countArray[0], 0, M * sizeof(T));
-
-		foreach(a, [&countArray](const size_t, const T val) -> void {
-			++countArray[val];
+	inline Array<size_t> insertion_argsort(Array<T>& a) noexcept {
+		Array<ArgVal<T>> temp_vals(a.length);
+		map(temp_vals, [&a](const size_t& i, const ArgVal<T>&) -> ArgVal<T> {
+			return ArgVal<T>(i, a[i]);
 		});
 
-		for (T i = 1; i <= M; ++i)
-			countArray[i] += countArray[i - 1];
+		insertion_sort(temp_vals);
 
-		Array<T> output(N);
-		for (size_t i = N - 1; i > 0; --i){
-			output[countArray[a[i]] - 1] = a[i];
-			--countArray[a[i]];
-		}
-		memmove(&a[0], &output[0], a.length * sizeof(T));
+		Array<size_t> indices(a.length);
+		return map(indices, [&temp_vals](const size_t& i, const size_t&) -> size_t {
+			return temp_vals[i].indice;
+		});
 	}
 
 	template<typename T>