C++Talk.NET

cg · Guest

/*

Hi,

This file is compilable for your coding pleasure. :)

I have sort of a strange question. I am using class templates to
guarantee that a set of functionality will be compiled inline rather than
be evaluate to a function call, for performance.

First of all, is this a valid/justifiable use of class templates, and
secondly, can I declare a template class with no argument list?

For background -- I'm essentially creating a 2-dimensional array which
can be accessed with a negative index (or a positive index which would
normally be "out of bounds") by creating a buffer zone around the
"interesting" portion of the array. To give an example (best viewed with
fixed font):

0 0 0 0 0
0 1 1 1 0
0 1 1 1 0
0 1 1 1 0
0 0 0 0 0

In the diagram above, I would call the middle portion of the array
containing the values of 1 "interesting", and the parts containing zeros
"uninteresting".

The template classes I've created allow me to access the interesting
portion of the diagram above starting at index (0,0), whereas the
uninteresting portion starts at (-1,-1).

Here is my code, which hopefully will make it more clear: (by the way --
I do realize that the following code is not highly optimized, so don't
feel like you need to point that out)

*/

template <int W, int B> class BoardRow
{

private:
char m_row[W+B*2];

public:
char &operator[](int x)
{
return m_row[x+B];
}
};

template <int WIDTH, int HEIGHT, int BUFFER> class BoardRows
{

private:
BoardRow<WIDTH, BUFFER> m_rows[HEIGHT+BUFFER*2];

public:
BoardRow<WIDTH, BUFFER> &operator[](int y)
{
return m_rows[y+BUFFER];
}
};

template <int I> class CheckerboardData
{

private:
BoardRows<8,8,2> m_rows;

public:
char getNotationSquare(int sqNum)
{
int sqRow = (sqNum-1) / 4;
int sqCol = (sqNum - 1 - sqRow * 4) * 2 + (sqRow+1) % 2;
return m_rows[sqRow][sqCol];
}

void setNotationSquare(int sqNum, char sqType)
{
int sqRow = (sqNum-1) / 4;
int sqCol = (sqNum - 1 - sqRow * 4) * 2 + (sqRow+1) % 2;
m_rows[sqRow][sqCol] = sqType;
}

BoardRow<8,2> &operator[](int y)
{
return m_rows[y];
}

};

typedef CheckerboardData<0> CheckerBoardDataType;

/*

Note that my CheckerboardData template class requires a parameter <I>
which is never even used inside of the template. I put that parameter in
to allow the class to compile, and for no other reason. Since I'm writing
this code for pleasure, I'm very picky about it and the unneeded template
argument bothers me.

What should I do instead?

*/

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kanze@gabi-soft.fr · Guest

cg <nunya (AT) damspam (DOT) com> wrote

Ulrich Eckhardt · Guest

cg wrote:

cg · Guest

[email]kanze (AT) gabi-soft (DOT) fr[/email] wrote in
news:d6652001.0410270029.7e43eac0 (AT) posting (DOT) google.com:

kanze@gabi-soft.fr · Guest

cg <nunya (AT) damspam (DOT) com> wrote

cg · Guest

[email]kanze (AT) gabi-soft (DOT) fr[/email] wrote in
news:d6652001.0410290155.47141e0e (AT) posting (DOT) google.com:

kanze@gabi-soft.fr · Guest

cg <nunya (AT) damspam (DOT) com> wrote