__uuidof Operator
Microsoft Specific
Retrieves the GUID attached to the expression.
__uuidof (
expression
)
Remarks
The expression can be a type name, pointer, reference, or array of that type, a template specialized on these types, or a variable of these types. The argument is valid as long as the compiler can use it to find the attached GUID.
A special case of this intrinsic is when either 0 or NULL is supplied as the argument. In this case, __uuidof will return a GUID made up of zeros.
Use this keyword to extract the GUID attached to:
注意
In a debug build, __uuidof always initializes an object dynamically (at runtime). In a release build, __uuidof can statically (at compile time) initialize an object.
Example
The following code (compiled with ole32.lib) will display the uuid of a library block created with the module attribute:
// expre_uuidof.cpp
// compile with: ole32.lib
#include "stdio.h"
#include "windows.h"
[emitidl];
[module(name="MyLib")];
[export]
struct stuff {
int i;
};
int main() {
LPOLESTR lpolestr;
StringFromCLSID(__uuidof(MyLib), &lpolestr);
wprintf_s(L"%s", lpolestr);
CoTaskMemFree(lpolestr);
}
Comments
In cases where the library name is no longer in scope, you can use __LIBID_ instead of __uuidof. For example:
StringFromCLSID(__LIBID_, &lpolestr);
END Microsoft Specific