RE: [Plib-devel] ssg Borland

[Fay J. F C. AAC/W. <joh...@eg...>]

The variable type "sgMat4" is typedef'ed to "sgFloat [4][4]", so I think the
argument is equivalent to

const sgFloat m[4][4]

This is a pointer to a constant array rather than being a constant pointer
to an array.  As such, an assignment like

m = w ;

is legal while an assignment like

m[0][0] = 1.0 ;

is not legal.  Or so I surmise.  The MSVC help files say this about "const":

<begin quote>
The const keyword can also be used in pointer declarations.

char *const aptr = mybuf;  // Constant pointer

*aptr = 'a';       // Legal
aptr = yourbuf;    // Error

A pointer to a variable declared as const can be assigned only to a pointer
that is also declared as const.

const char *bptr = mybuf;  // Pointer to constant data

*bptr = 'a';       // Error
bptr = yourbuf;    // Legal
<end quote>

John F. Fay
joh...@eg...



-----Original Message-----
From: pli...@li...
[mailto:pli...@li...]On Behalf Of Wolfram Kuss
Sent: Tuesday, May 04, 2004 7:58 AM
To: pli...@li...
Subject: Re: [Plib-devel] ssg Borland

<snip>

>ssgVtxTable.cxx
>
>Within void ssgVtxTable::transform ( const sgMat4 m ) there is a line that
>says:
>
> 
>
>m = w;

Maybe this is a stupid question, but why do other compilers not even
warn? I checked and MSVC has no problems with that line.

Bye bye,
Wolfram.