Re: code review?

----- Original Message ----- 
From: "Bill Coffman"
.
.
> Anyway, here's the other thing to try (please correct
> any errors as I am programming to email):
>
> #include <stdio.h>
>
> union _pdl_nan_bits_float {unsigned char c[4]; float f;}
> union _pdl_nan_bits_double {unsigned char c[8]; double d;}
>
>
> #define NaN_float (((union _pdl_nan_bits_float)   \
>        {{0x7f, 0xff, 0xff, 0x7f}}) . f)
> #define NaN_double (((union _pdl_nan_bits_double) \
>        {{0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f}}) . d)
>
> int main() {
>
> if(NaN_float != NaN_float) printf("ok1\n");
> if(NaN_double != NaN_double) printf("ok2\n");
>
> return 0;
> }
>

The only error I fixed was to add the missing semi-colon at the end of the 2
'union ..' declarations. It then works fine with gcc, but with Visual
Studio, it still won't compile:

-----------------------------------------------
F:\C>cat try.c
union _pdl_nan_bits_float {unsigned char c[4]; float f;};
union _pdl_nan_bits_double {unsigned char c[8]; double d;};


#define NaN_float (((union _pdl_nan_bits_float)   \
       {{0x7f, 0xff, 0xff, 0x7f}}) . f)
#define NaN_double (((union _pdl_nan_bits_double) \
       {{0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f}}) . d)

int main() {

if(NaN_float != NaN_float) printf("ok1\n");
if(NaN_double != NaN_double) printf("ok2\n");

return 0;
}
F:\C>cl try.c
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.00.9466 for 80x86
Copyright (C) Microsoft Corporation 1984-2001. All rights reserved.

try.c
try.c(12) : error C2059: syntax error : '{'
try.c(13) : error C2059: syntax error : '{'
-----------------------------------------------------

Is there any reason we ought not make the following change to pdlcore.h.PL:

#ifdef _MSC_VER
#include <math.h>
#define NaN_float ((float)sqrt(-1))
#define NaN_double ((double)sqrt(-1))
#else
#define NaN_float (((union {unsigned char c[4]; float d;})   \
        {{0x7f, 0xff, 0xff, 0x7f}}) . d)
#define NaN_double (((union {unsigned char c[8]; double d;}) \
        {{0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f}}) . d)
#endif

(Actually, I'm not sure that it's necessary to '#include <math.h>'.)

When I make that change in pdlcore.h.PL, I find that PDL builds and tests
fine with Visual Studio.

Cheers,
Rob