Allocating Space in the Far Heap in Near Data Models

ID: Q87637

7.00 | 1.00 1.50 MS-DOS | WINDOWS kbprg

The information in this article applies to:

Microsoft C/C++ compiler for MS-DOS, version 7.0
Microsoft Visual C++ for Windows, versions 1.0 and 1.5

SUMMARY

To force an object to be allocated in the far heap in a small or medium memory model C++ program, use the __far keyword in front of the object being allocated.

For example, where T is either an implicit or user-defined type, the syntax would be:

   new __far T;

This returns a far pointer to an object of type T allocated in the far heap. However, if type T is a near class, the following error will be generated:

   C2512: no appropriate default constructor available

This error is generated because the far pointer cannot be converted to a near pointer when the constructor is invoked.

The programmer must then declare the class as a far class or provide a special constructor that takes a far "this" pointer.

Additional reference words: kbinf 7.00 1.00 1.50 KBCategory: kbprg KBSubcategory: CPPLngIss Keywords : kb16bitonly

Last Reviewed: July 18, 1997