A5: code complete

6 files changed, 349 insertions, 102 deletions

diff --git a/a5/Makefile b/a5/Makefile
index 282dfa9..6869fd8 100644
--- a/a5/Makefile
+++ b/a5/Makefile
@@ -1,4 +1,4 @@
 all: matrix
 
-matrix: matrix.cc Makefile imatrix.h imatrix_nm.h matrix.h
-	g++ -O2 -Wall -Werror -Wextra -Wconversion -std=c++20 $< -o $@
+matrix: matrix.cc Makefile imatrix.h imatrix_nm.h matrix.h Makefile
+	g++ -g -O2 -Wall -Werror -Wextra -Wconversion -std=c++20 $< -o $@
diff --git a/a5/exercise.tex b/a5/exercise.tex
index 6889950..9491afe 100644
--- a/a5/exercise.tex
+++ b/a5/exercise.tex
@@ -60,4 +60,7 @@ needed. This I think is actually not that good.
 Adding the requirement to each of the member functions might be
 better.
 
+
+I actually made some errors in the matrix subscripts in the matrix
+multiplication/division code, which was shown to me by an assertion.
 \end{document}
diff --git a/a5/imatrix.h b/a5/imatrix.h
index f96cb0c..b13f60d 100644
--- a/a5/imatrix.h
+++ b/a5/imatrix.h
@@ -119,7 +119,7 @@ public:
 				out.m(i,j) = 0;
 				for(std::size_t k = 0; k < other.w; ++k)
 				{
-					out.m(i,j) += m(i, j) * other.m(k, j);
+					out.m(i,j) += m(i,k) * other.m(k,j);
 				}
 			}
 		}
@@ -147,7 +147,7 @@ public:
 				out.m(i,j) = 0;
 				for(std::size_t k = 0; k < other.w; ++k)
 				{
-					out.m(i,j) += m(i, j) / other.m(k, j);
+					out.m(i,j) += m(i,k) / other.m(k,j);
 				}
 			}
 		}
@@ -201,4 +201,6 @@ private:
 	std::valarray<int> data; // default initialized to empty
 	std::size_t w{}; // default initialized to 0
 	std::size_t h{}; // default initialized to 0
+
+	friend std::ostream& operator<<(std::ostream& s, const Imatrix& m);
 };
diff --git a/a5/imatrix_nm.h b/a5/imatrix_nm.h
index 970031a..f69a099 100644
--- a/a5/imatrix_nm.h
+++ b/a5/imatrix_nm.h
@@ -5,32 +5,32 @@
 #include <valarray>
 #include <stdexcept>
 
-template<std::size_t W, std::size_t H>
+template<std::size_t N, std::size_t M>
 class ImatrixNM
 {
 public:
 	ImatrixNM()
-		: data(0, W * H)
+		: data(0, N * M)
 	{
 	}
 
-	ImatrixNM(ImatrixNM<W, H>&& other)
+	ImatrixNM(ImatrixNM<N, M>&& other)
 	{
 		*this = std::move(other);
 	}
 
-	ImatrixNM(const ImatrixNM<W, H>& other)
+	ImatrixNM(const ImatrixNM<N, M>& other)
 	{
 		*this = other;
 	}
 
-	ImatrixNM& operator=(ImatrixNM<W, H>&& other)
+	ImatrixNM& operator=(ImatrixNM<N, M>&& other)
 	{
 		data = std::move(other.data);
 		return *this;
 	}
 
-	ImatrixNM& operator=(const ImatrixNM<W, H>& other)
+	ImatrixNM& operator=(const ImatrixNM<N, M>& other)
 	{
 		data = other.data;
 		return *this;
@@ -38,70 +38,70 @@ public:
 
 	int& m(std::size_t x, std::size_t y)
 	{
-		if(x >= W || y >= H) throw std::out_of_range("Subscript out of range.");
-		return data[x + y * W];
+		if(x >= N || y >= M) throw std::out_of_range("Subscript out of range.");
+		return data[x + y * N];
 	}
 
 	const int& m(std::size_t x, std::size_t y) const
 	{
-		if(x >= W || y >= H) throw std::out_of_range("Subscript out of range.");
-		return data[x + y * W];
+		if(x >= N || y >= M) throw std::out_of_range("Subscript out of range.");
+		return data[x + y * N];
 	}
 
-	ImatrixNM<W, H> operator+(const ImatrixNM<W, H>& other) const
+	ImatrixNM<N, M> operator+(const ImatrixNM<N, M>& other) const
 	{
 		ImatrixNM m(*this);
 		m.data += other.data;
 		return m;
 	}
 
-	ImatrixNM<W, H> operator+(int val)
+	ImatrixNM<N, M> operator+(int val)
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data += val;
 		return m;
 	}
 
-	ImatrixNM<W, H> operator-(const ImatrixNM<W, H>& other) const
+	ImatrixNM<N, M> operator-(const ImatrixNM<N, M>& other) const
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data -= other.data;
 		return m;
 	}
 
-	ImatrixNM <W, H>operator-(int val)
+	ImatrixNM <N, M>operator-(int val)
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data -= val;
 		return m;
 	}
 
-	ImatrixNM<W, H> operator%(const ImatrixNM<W, H>& other) const
+	ImatrixNM<N, M> operator%(const ImatrixNM<N, M>& other) const
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data %= other.data;
 		return m;
 	}
 
-	ImatrixNM<W, H> operator%(int val)
+	ImatrixNM<N, M> operator%(int val)
 	{
 		ImatrixNM m(*this);
 		m.data %= val;
 		return m;
 	}
 
-	template<std::size_t N>
-	ImatrixNM<W, N> operator*(const ImatrixNM<H, N>& other) const
+	template<std::size_t R>
+	ImatrixNM<N, R> operator*(const ImatrixNM<M, R>& other) const
 	{
-		ImatrixNM<W, N> out;
-		for(std::size_t i = 0; i < W; ++i)
+		ImatrixNM<N, R> out;
+		for(std::size_t i = 0; i < N; ++i)
 		{
 			for(std::size_t j = 0; j < N; ++j)
 			{
 				out.m(i,j) = 0;
-				for(std::size_t k = 0; k < H; ++k)
+				for(std::size_t k = 0; k < M; ++k)
 				{
-					out.m(i,j) += m(i, j) * other.m(k, j);
+					out.m(i,j) += m(i,k) * other.m(k,j);
 				}
 			}
 		}
@@ -109,25 +109,25 @@ public:
 		return out;
 	}
 
-	ImatrixNM<W, H> operator*(int val) const
+	ImatrixNM<N, M> operator*(int val) const
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data *= val;
 		return m;
 	}
 
-	template<std::size_t N>
-	ImatrixNM<W, N> operator/(const ImatrixNM<H, N>& other) const
+	template<std::size_t R>
+	ImatrixNM<N, R> operator/(const ImatrixNM<M, R>& other) const
 	{
-		ImatrixNM<W, N> out;
-		for(std::size_t i = 0; i < W; ++i)
+		ImatrixNM<N, R> out;
+		for(std::size_t i = 0; i < N; ++i)
 		{
 			for(std::size_t j = 0; j < N; ++j)
 			{
 				out.m(i,j) = 0;
-				for(std::size_t k = 0; k < H; ++k)
+				for(std::size_t k = 0; k < M; ++k)
 				{
-					out.m(i,j) += m(i, j) / other.m(k, j);
+					out.m(i,j) += m(i,k) / other.m(k,j);
 				}
 			}
 		}
@@ -135,9 +135,9 @@ public:
 		return out;
 	}
 
-	ImatrixNM<W, H> operator/(int val) const
+	ImatrixNM<N, M> operator/(int val) const
 	{
-		ImatrixNM<W, H> m(*this);
+		ImatrixNM<N, M> m(*this);
 		m.data /= val;
 		return m;
 	}
@@ -156,9 +156,9 @@ public:
 
 	std::vector<int> Row(std::size_t n) const
 	{
-		if(n >= H) throw std::out_of_range("Subscript out of range.");
+		if(n >= M) throw std::out_of_range("Subscript out of range.");
 		std::vector<int> out;
-		for(std::size_t x = 0; x < W; ++x)
+		for(std::size_t x = 0; x < N; ++x)
 		{
 			out.push_back(m(x, n));
 		}
@@ -167,9 +167,9 @@ public:
 
 	std::vector<int> Column(std::size_t n) const
 	{
-		if(n >= W) throw std::out_of_range("Subscript out of range.");
+		if(n >= N) throw std::out_of_range("Subscript out of range.");
 		std::vector<int> out;
-		for(std::size_t y = 0; y < H; ++y)
+		for(std::size_t y = 0; y < M; ++y)
 		{
 			out.push_back(m(n, y));
 		}
diff --git a/a5/matrix.cc b/a5/matrix.cc
index 01744fa..4a34fa0 100644
--- a/a5/matrix.cc
+++ b/a5/matrix.cc
@@ -2,26 +2,226 @@
 #include "imatrix_nm.h"
 #include "matrix.h"
 
+#include <iostream>
+
+template<typename T, std::size_t N, std::size_t M>
+std::ostream& operator<<(std::ostream& s, const Matrix<T,N,M>& m)
+{
+	for(auto j = 0u; j < M; ++j)
+	{
+		for(auto i = 0u; i < N; ++i)
+		{
+			s << m.m(i,j) << ' ';
+		}
+		s << '\n';
+	}
+	return s;
+}
+
+template<std::size_t N, std::size_t M>
+std::ostream& operator<<(std::ostream& s, const ImatrixNM<N,M>& m)
+{
+	for(auto j = 0u; j < M; ++j)
+	{
+		for(auto i = 0u; i < N; ++i)
+		{
+			s << m.m(i,j) << ' ';
+		}
+		s << '\n';
+	}
+	return s;
+}
+
+std::ostream& operator<<(std::ostream& s, const Imatrix& m)
+{
+	for(auto j = 0u; j < m.h; ++j)
+	{
+		for(auto i = 0u; i < m.w; ++i)
+		{
+			s << m.m(i,j) << ' ';
+		}
+		s << '\n';
+	}
+	return s;
+}
+
 struct Chess_piece
 {
+	Chess_piece operator*(const Chess_piece&) const {return {};}
+	Chess_piece operator/(const Chess_piece&) const {return {};}
+	Chess_piece operator+(const Chess_piece&) const {return {};}
+	Chess_piece operator-(const Chess_piece&) const {return {};}
+
+	Chess_piece& operator*=(const Chess_piece&){return *this;}
+	Chess_piece& operator/=(const Chess_piece&){return *this;}
+	Chess_piece& operator+=(const Chess_piece&){return *this;}
+	Chess_piece& operator-=(const Chess_piece&){return *this;}
+
+	Chess_piece operator*(int) const {return {};}
+	Chess_piece operator/(int) const {return {};}
+	Chess_piece operator+(int) const {return {};}
+	Chess_piece operator-(int) const {return {};}
+
+	Chess_piece& operator*=(int){return *this;}
+	Chess_piece& operator/=(int){return *this;}
+	Chess_piece& operator+=(int){return *this;}
+	Chess_piece& operator-=(int){return *this;}
 };
 
+std::ostream& operator<<(std::ostream& s, const Chess_piece&)
+{
+	s << "Chess_piece";
+	return s;
+}
+
+template<typename M1, typename M2>
+void test(M1& m1, M2& m2)
+{
+	std::cout << "m1=\n" << m1 << '\n';
+	std::cout << "m2=\n" << m2 << '\n';
+
+	{
+		auto m3 = m1 * m2;
+		std::cout << "m1*m2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 / m2;
+		std::cout << "m1/m2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 + m1;
+		std::cout << "m1+m1\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 - m1;
+		std::cout << "m1-m1\n" << m3 << '\n';
+	}
+
+	if constexpr (supports_modulo<M1, M1>)
+	{
+		auto m3 = m1 % m1;
+		std::cout << "m1%m1\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 * 2;
+		std::cout << "m1*2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 / 2;
+		std::cout << "m1/2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 + 2;
+		std::cout << "m1+2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1 - 2;
+		std::cout << "m1-2\n" << m3 << '\n';
+	}
+
+	if constexpr (supports_modulo<M1, int>)
+	{
+		auto m3 = m1 % 2;
+		std::cout << "m1%2\n" << m3 << '\n';
+	}
+
+	{
+		auto m3 = m1;
+		m3.Move({0,0}, {1,1});
+		std::cout << "m3.Move (copy assign)\n" << m3 << '\n';
+	}
+
+	{
+		auto m3(m1);
+		auto r = m3.Row(0);
+		std::cout << "m3.Row (copy ctor)\n";
+		for(auto i : r) std::cout << i << ' ';
+		std::cout << "\n\n";
+	}
+
+	{
+		auto m3(std::move(m1));
+		auto c = m3.Column(0);
+		std::cout << "m3.Column (move ctor)\n";
+		for(auto i : c) std::cout << i << ' ';
+		std::cout << "\n\n";
+	}
+
+	{
+		auto m3 = std::move(m2);
+		std::cout << "m3 (move assign)\n" << m3 << '\n';
+	}
+}
+
 int main()
 {
-	Matrix<double, 3, 5> m1;
-	m1 = m1 + 2;
-	m1.m(2,2) = 42;
-	try
+	std::cout << "Imatrix:\n";
 	{
-		m1.m(6,6) = 0;
+		Imatrix m1(3,2);
+		m1.m(0,0) = 1; m1.m(1,0) = 2; m1.m(2,0) = 3;
+		m1.m(0,1) = 4; m1.m(1,1) = 5; m1.m(2,1) = 6;
+
+		Imatrix m2(2,3);
+		m2.m(0,0) = 1; m2.m(1,0) = 2;
+		m2.m(0,1) = 3; m2.m(1,1) = 4;
+		m2.m(0,2) = 5; m2.m(1,2) = 6;
+
+		test(m1, m2);
 	}
-	catch(...)
+
+	std::cout << "ImatrixNM<..,..>:\n";
 	{
-		// expected
+		ImatrixNM<3, 2> m1;
+		m1.m(0,0) = 1; m1.m(1,0) = 2; m1.m(2,0) = 3;
+		m1.m(0,1) = 4; m1.m(1,1) = 5; m1.m(2,1) = 6;
+
+		ImatrixNM<2, 3> m2;
+		m2.m(0,0) = 1; m2.m(1,0) = 2;
+		m2.m(0,1) = 3; m2.m(1,1) = 4;
+		m2.m(0,2) = 5; m2.m(1,2) = 6;
+
+		test(m1, m2);
 	}
-	Matrix<double, 5, 2> m2;
-	auto m3 = m1 * m2;
 
-	Matrix<Chess_piece, 2, 2> c1;
-	auto c2 = c1 + 42;
+	std::cout << "Matrix<int, .., ..>:\n";
+	{
+		Matrix<int, 3, 2> m1;
+		m1.m(0,0) = 1; m1.m(1,0) = 2; m1.m(2,0) = 3;
+		m1.m(0,1) = 4; m1.m(1,1) = 5; m1.m(2,1) = 6;
+
+		Matrix<int, 2, 3> m2;
+		m2.m(0,0) = 1; m2.m(1,0) = 2;
+		m2.m(0,1) = 3; m2.m(1,1) = 4;
+		m2.m(0,2) = 5; m2.m(1,2) = 6;
+
+		test(m1, m2);
+	}
+
+	std::cout << "Matrix<double, .., ..>:\n";
+	{
+		Matrix<double, 3, 2> m1;
+		m1.m(0,0) = 1; m1.m(1,0) = 2; m1.m(2,0) = 3;
+		m1.m(0,1) = 4; m1.m(1,1) = 5; m1.m(2,1) = 6;
+
+		Matrix<double, 2, 3> m2;
+		m2.m(0,0) = 1; m2.m(1,0) = 2;
+		m2.m(0,1) = 3; m2.m(1,1) = 4;
+		m2.m(0,2) = 5; m2.m(1,2) = 6;
+
+		test(m1, m2);
+	}
+
+	std::cout << "Matrix<Chess_piece, .., ..>:\n";
+	{
+		Matrix<Chess_piece, 3, 2> m1;
+		Matrix<Chess_piece, 2, 3> m2;
+		test(m1, m2);
+	}
 }
diff --git a/a5/matrix.h b/a5/matrix.h
index af83683..6d880e2 100644
--- a/a5/matrix.h
+++ b/a5/matrix.h
@@ -4,33 +4,71 @@
 #include <utility>
 #include <valarray>
 #include <stdexcept>
+#include <concepts>
 
-template<typename T, std::size_t W, std::size_t H>
+template<typename T1, typename T2>
+concept supports_modulo =
+	requires(T1 t1, T2 t2)
+	{
+		t1 % t2;
+	};
+
+template<typename T>
+concept supports_matrix =
+	requires(T a, T b, int i)
+	{
+		a * b;
+		a / b;
+		a + b;
+		a - b;
+
+		a * i;
+		a / i;
+		a + i;
+		a - i;
+
+		a *= b;
+		a /= b;
+		a += b;
+		a -= b;
+
+		a *= i;
+		a /= i;
+		a += i;
+		a -= i;
+
+		a = b;
+		a = {};
+	};
+
+
+template<typename T, std::size_t N, std::size_t M>
+	requires supports_matrix<T>
 class Matrix
 {
 public:
 	Matrix()
-		: data(T{}, W * H)
+		: data(T{}, N * M)
 	{
 	}
 
-	Matrix(Matrix<T, W, H>&& other)
+	Matrix(Matrix<T, N, M>&& other)
 	{
 		*this = std::move(other);
 	}
 
-	Matrix(const Matrix<T, W, H>& other)
+	Matrix(const Matrix<T, N, M>& other)
 	{
 		*this = other;
 	}
 
-	Matrix& operator=(Matrix<T, W, H>&& other)
+	Matrix& operator=(Matrix<T, N, M>&& other)
 	{
 		data = std::move(other.data);
 		return *this;
 	}
 
-	Matrix& operator=(const Matrix<T, W, H>& other)
+	Matrix& operator=(const Matrix<T, N, M>& other)
 	{
 		data = other.data;
 		return *this;
@@ -38,70 +76,74 @@ public:
 
 	T& m(std::size_t x, std::size_t y)
 	{
-		if(x >= W || y >= H) throw std::out_of_range("Subscript out of range.");
-		return data[x + y * W];
+		if(x >= N) throw std::out_of_range("Subscript x out of range.");
+		if(y >= M) throw std::out_of_range("Subscript y out of range.");
+		return data[x + y * N];
 	}
 
 	const T& m(std::size_t x, std::size_t y) const
 	{
-		if(x >= W || y >= H) throw std::out_of_range("Subscript out of range.");
-		return data[x + y * W];
+		if(x >= N) throw std::out_of_range("Subscript x out of range.");
+		if(y >= M) throw std::out_of_range("Subscript y out of range.");
+		return data[x + y * N];
 	}
 
-	Matrix<T, W, H> operator+(const Matrix<T, W, H>& other) const
+	Matrix<T, N, M> operator+(const Matrix<T, N, M>& other) const
 	{
 		Matrix m(*this);
 		m.data += other.data;
 		return m;
 	}
 
-	Matrix<T, W, H> operator+(T val)
+	Matrix<T, N, M> operator+(int val)
 	{
-		Matrix<T, W, H> m(*this);
-		m.data += val;
+		Matrix<T, N, M> m(*this);
+		for(auto& d : m.data) d += val;
 		return m;
 	}
 
-	Matrix<T, W, H> operator-(const Matrix<T, W, H>& other) const
+	Matrix<T, N, M> operator-(const Matrix<T, N, M>& other) const
 	{
-		Matrix<T, W, H> m(*this);
+		Matrix<T, N, M> m(*this);
 		m.data -= other.data;
 		return m;
 	}
 
-	Matrix <T, W, H>operator-(T val)
+	Matrix <T, N, M> operator-(int val)
 	{
-		Matrix<T, W, H> m(*this);
-		m.data -= val;
+		Matrix<T, N, M> m(*this);
+		for(auto& d : m.data) d -= val;
 		return m;
 	}
 
-	Matrix<T, W, H> operator%(const Matrix<T, W, H>& other) const
+	Matrix<T, N, M> operator%(const Matrix<T, N, M>& other) const
+		requires(supports_modulo<T,T>)
 	{
-		Matrix<T, W, H> m(*this);
+		Matrix<T, N, M> m(*this);
 		m.data %= other.data;
 		return m;
 	}
 
-	Matrix<T, W, H> operator%(T val)
+	Matrix<T, N, M> operator%(int val)
+		requires(supports_modulo<T,int>)
 	{
 		Matrix m(*this);
-		m.data %= val;
+		for(auto& d : m.data) d %= val;
 		return m;
 	}
 
-	template<std::size_t N>
-	Matrix<T, W, N> operator*(const Matrix<T, H, N>& other) const
+	template<std::size_t R>
+	Matrix<T, N, R> operator*(const Matrix<T, M, R>& other) const
 	{
-		Matrix<T, W, N> out;
-		for(std::size_t i = 0; i < W; ++i)
+		Matrix<T, N, R> out;
+		for(std::size_t i = 0; i < N; ++i)
 		{
-			for(std::size_t j = 0; j < N; ++j)
+			for(std::size_t j = 0; j < R; ++j)
 			{
 				out.m(i,j) = {};
-				for(std::size_t k = 0; k < H; ++k)
+				for(std::size_t k = 0; k < M; ++k)
 				{
-					out.m(i,j) += m(i, j) * other.m(k, j);
+					out.m(i,j) += m(i,k) * other.m(k,j);
 				}
 			}
 		}
@@ -109,25 +151,25 @@ public:
 		return out;
 	}
 
-	Matrix<T, W, H> operator*(T val)
+	Matrix<T, N, M> operator*(int val)
 	{
-		Matrix<T, W, H> m(*this);
-		m.data *= val;
+		Matrix<T, N, M> m(*this);
+		for(auto& d : m.data) d *= val;
 		return m;
 	}
 
-	template<std::size_t N>
-	Matrix<T, W, N> operator/(const Matrix<T, H, N>& other) const
+	template<std::size_t R>
+	Matrix<T, N, R> operator/(const Matrix<T, M, R>& other) const
 	{
-		Matrix<T, W, N> out;
-		for(std::size_t i = 0; i < W; ++i)
+		Matrix<T, N, R> out;
+		for(std::size_t i = 0; i < N; ++i)
 		{
-			for(std::size_t j = 0; j < N; ++j)
+			for(std::size_t j = 0; j < R; ++j)
 			{
 				out.m(i,j) = {};
-				for(std::size_t k = 0; k < H; ++k)
+				for(std::size_t k = 0; k < M; ++k)
 				{
-					out.m(i,j) += m(i, j) / other.m(k, j);
+					out.m(i,j) += m(i,k) / other.m(k,j);
 				}
 			}
 		}
@@ -135,10 +177,10 @@ public:
 		return out;
 	}
 
-	Matrix<T, W, H> operator/(T val) const
+	Matrix<T, N, M> operator/(int val) const
 	{
-		Matrix<T, W, H> m(*this);
-		m.data /= val;
+		Matrix<T, N, M> m(*this);
+		for(auto& d : m.data) d /= val;
 		return m;
 	}
 
@@ -156,9 +198,9 @@ public:
 
 	std::vector<T> Row(std::size_t n) const
 	{
-		if(n >= H) throw std::out_of_range("Subscript out of range.");
+		if(n >= M) throw std::out_of_range("Subscript out of range.");
 		std::vector<T> out;
-		for(std::size_t x = 0; x < W; ++x)
+		for(std::size_t x = 0; x < N; ++x)
 		{
 			out.push_back(m(x, n));
 		}
@@ -167,9 +209,9 @@ public:
 
 	std::vector<T> Column(std::size_t n) const
 	{
-		if(n >= W) throw std::out_of_range("Subscript out of range.");
+		if(n >= N) throw std::out_of_range("Subscript out of range.");
 		std::vector<T> out;
-		for(std::size_t y = 0; y < H; ++y)
+		for(std::size_t y = 0; y < M; ++y)
 		{
 			out.push_back(m(n, y));
 		}