Microsoft-Specific Modifiers
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This section describes Microsoft-specific extensions to C++ in the following areas:
Based addressing, the practice of using a pointer as a base from which other pointers can be offset
Extended storage-class attributes declared with the __declspec keyword
The __w64 keyword
Many of the Microsoft-specific keywords can be used to modify declarators to form derived types. For more information about declarators, see Declarators.
Microsoft-Specific Keywords
| Keyword | Meaning | Used to Form Derived Types? |
|---|---|---|
| __based | The name that follows declares a 32-bit offset to the 32-bit base contained in the declaration. | Yes |
| __cdecl | The name that follows uses the C naming and calling conventions. | Yes |
| __declspec | The name that follows specifies a Microsoft-specific storage-class attribute. | No |
| __fastcall | The name that follows declares a function that uses registers, when available, instead of the stack for argument passing. | Yes |
| __restrict | Similar to __declspec(restrict), but for use on variables. | No |
| __stdcall | The name that follows specifies a function that observes the standard calling convention. | Yes |
| __w64 | Marks a data type as being larger on a 64-bit compiler. | No |
| __unaligned | Specifies that a pointer to a type or other data is not aligned.. | No |
| __vectorcall | The name that follows declares a function that uses registers, including SSE registers, when available, instead of the stack for argument passing. | Yes |