Q43486: C: Automatic Casting from Near Pointer to Far Pointer

Article: Q43486
Product(s): See article
Version(s): 5.10   | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | | mspl13_c
Last Modified: 17-MAY-1989

In Microsoft C, the automatic type casting from a near pointer to a
far pointer that is performed by the compiler will make the segment
address of the resulting pointer the same as that of DGroup. In those
cases, no explicit type casting is needed.

Two of the cases of the automatic casting are shown in the following
sample program:

#include <malloc.h>

void foo (char far *) ;
void main (void)
{
char far *lpChar ;
char * npChar ;
lpChar = malloc( 100 );   /* malloc is mapped to _nmalloc,
                          ** and returns near pointer, automatic type
                          ** casting is performed with assignment */

foo( npChar ) ;           /* npChar is converted to a far pointer
                          ** with the segment address to be DS */
}

void foo (char far * p)
{
}

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