New C++. Why the flowing code cannot be compiled?

[Chaokai Ching]

//---------------------------------------------------------------------------
// Matrix.h
//---------------------------------------------------------------------------
#if !defined(Matrix_H)
Â* #define Matrix_H
Â* #include <windows.h>
Â* #include <GL/gl.h>
Â* #include <iostream>
Â* #include <vector>
using namespace std;



class Matrix
{
private:
Â* static const int NUM_ELEMENTS = 16;
Â* vector<GLfloat> elements(NUM_ELEMENTS);
public:
Â* Matrix( void );
Â* void loadMatrix( Matrix other );
Â* void matrixMultiply( Matrix other );
Â* GLfloat getElement( int index );
Â* void toString();
Â* ~Matrix();
};

#endif
-----------------------------------------------------------------------
Matrix::Matrix( void )
{
Â* for ( int i = 0; i < NUM_ELEMENTS; i++ )
Â* {
Â*Â*Â* if ( i % 5 == 0 )
Â*Â*Â* {
Â*Â*Â*Â*Â* elements[i] = 1.0;
Â*Â*Â* }
Â*Â*Â* else
Â*Â*Â* {
Â*Â*Â*Â*Â* elements[i] = 0.0;
Â*Â*Â* }
Â* }
}
const int Matrix::NUM_ELEMENTS;

-------------------------------------------------------------------------
Howver, if I change vector<GLfloat> elements(NUM_ELEMENTS) to vector<GLfloat> elements(), it allows me to compile.

Thanks

Kai



--


殘ç‡*æ˜*ç´…å�Šé‚ŠåŠ�，æ„�海飄零一å*¤ç‡ˆ(Kai)

[Victor Bazarov]

"Chaokai Ching" <ch****@cis.ohio-state.edu> wrote...
//---------------------------------------------------------------------------
// Matrix.h
//---------------------------------------------------------------------------
#if !defined(Matrix_H)
 #define Matrix_H
 #include <windows.h>
 #include <GL/gl.h>
 #include <iostream>
 #include <vector>
using namespace std;

class Matrix
{
private:
 static const int NUM_ELEMENTS = 16;
 vector<GLfloat> elements(NUM_ELEMENTS);

You cannot initialise non-static members in the class defniniton. That's
what the constructors are for.

[...]
-------------------------------------------------------------------------
Howver, if I change vector<GLfloat> elements(NUM_ELEMENTS) to vector<GLfloat> elements(), it allows me to compile.

Of course it does. 'elements' becomes a function declaration.

V

[Ioannis Vranos]

Chaokai Ching wrote:

Howver, if I change vector<GLfloat> elements(NUM_ELEMENTS) to
vector<GLfloat> elements(), it allows me to compile.

The code fixed to compile:

//---------------------------------------------------------------------------
// Matrix.h
//---------------------------------------------------------------------------
#if !defined(Matrix_H)
#define Matrix_H
#include <windows.h>
#include <GL/gl.h>
#include <iostream>
#include <vector>
using namespace std;

class Matrix
{
private:
static const int NUM_ELEMENTS = 16;
vector<GLfloat> elements;
public:
Matrix( void );
void loadMatrix( Matrix other );
void matrixMultiply( Matrix other );
GLfloat getElement( int index );
void toString();
~Matrix();
};

#endif

Matrix::Matrix( void ): elements(NUM_ELEMENTS)
{
for ( int i = 0; i < NUM_ELEMENTS; i++ )
{
if ( i % 5 == 0 )
{
elements[i] = 1.0;
}
else
{
elements[i] = 0.0;
}
}
}

// Not needed
//const int Matrix::NUM_ELEMENTS;
int main() {}

--
Ioannis Vranos

http://www23.brinkster.com/noicys