Problems with self created template matrix class - c++

Question

I'm trying to write code that implemets a template for a matrix with boundary check and additional operators. However, I'm stuck at a SIGGSEGV right now.
The matrix is based on a vector class I wrote myself, too:
#ifndef VEKTOR_H
#define VEKTOR_H
#include "Exeptions.h"
template<typename T>
class vektor
{
private:
unsigned int length;
T* items;
public:
inline unsigned int getLength() const{return length;};
vektor():length(0),items(nullptr)
{
//ctor
}
virtual ~vektor()
{
delete [] items;
}
vektor(const vektor& other):length(other.getLength()),items(new T[length])
{
for(int i = 0;i<length;i++)
{
items[i]=other[i];
}
}
vektor(int len):length(len),items(new T[len])
{
}
vektor<T>& operator=(const vektor& rhs)
{
if (this == &rhs) return *this; // handle self assignment
//assignment operator
length = rhs.getLength();
items = new T[length];
for(int i = 0;i<length;i++)
{
items[i]=rhs[i];
}
return *this;
}
T& operator[](const unsigned int index)const
{
if(index >= 0 && index < length)
{
return items[index];
}
else throw out_of_bounds();
}
};
#endif // VEKTOR_H
Then the code for the matrix:
#ifndef MATRIX_H
#define MATRIX_H
#include "vektor.h"
template <typename T>
class matrix
{
private:
int columns;
vektor<T>* tabs;
public:
inline int getColCount()const{return columns;};
inline int getRowCount()const{return tabs[0].getLength();};
inline vektor<T>* getTabs()const{return tabs;};
matrix():columns(0),tabs(new vektor<T>(0))
{
//ctor
}
matrix(int columns, int rows):columns(columns),tabs(new vektor<T>[columns])
{
for(int i = 0; i< columns;i++)
{
tabs[i] = *new vektor<T>(rows);
}
}
virtual ~matrix()
{
delete tabs;
}
matrix(const matrix& other):rows(other.getColCount()),tabs(new vektor<T>(*other.getTabs()))
{
//copy ctor
}
matrix<T>& operator=(const matrix& rhs)
{
if (this == &rhs) return *this; // handle self assignment
//assignment operator
spalten = rhs.getColCount();
tabs = new vektor<T>(*rhs.getTabs());
return *this;
}
vektor<T>& operator[](unsigned int index)
{
return tabs[index];
}
};
#endif // MATRIX_H
A wrapper class that instantiates a matrix with string to create a menu-like structure:
MenUI::MenUI():selectedTab(3),selectedItem(4),menItems(matrix<string>(3,4))
{
menItems[0][0] = "File";
menItems[0][1] = "Edit";
menItems[0][2] = "View";
menItems[0][3] = "Search";
menItems[1][0] = "New";
menItems[1][1] = "Undo";
menItems[1][2] = "Perspectives";
menItems[1][3] = "Find";
menItems[2][0] = "Open...";
menItems[2][1] = "Redo";
menItems[2][2] = "Toolbars";
menItems[2][3] = "Find in Files";
}
And here the SIGSEGV happens at line tmp = menItems[selectedTab][i];
void MenUI::print()
{
int offset = 0;
string tmp;
for(unsigned int i = 0; i<menItems.getColCount();i++)
{
tmp = menItems[i][0];
if (i == selectedTab) cout << "|- " << setw(10) << tmp << " -";
else cout << "| " << setw(10) << tmp << " ";
}
cout << "|" << endl;
offset = selectedTab * (10 + 5);
for(unsigned int i = 1;i<menItems.getRowCount();i++)
{
tmp = menItems[selectedTab][i];
if(i == selectedItem) cout << string(offset-3, ' ') << "|> " << setw(10) << tmp << " <|" << endl;
else cout << string(offset-3, ' ') << "| " << setw(10) << tmp << " |" << endl;
}
}
As this is the first time I used templates, I'm a bit lost right now.
I'm using Code::Blocks IDE with GCC.
It would be really great if someone could point me in the right direction.
Thanks!

Answer 1

If selectedTab is 3 and you do tmp = menItems[selectedTab][i]; your code will seg fault because you are accessing outside the bounds of the memory.
I might have taken what you have written too literally and you change selectedTab