pointers_to_members
C++ Specific
Specifies whether a pointer to a class member can be declared before its associated class definition and is used to control the pointer size and the code required to interpret the pointer.
#pragma pointers_to_members( pointer-declaration, [most-general-representation] )
Remarks
You can place a pointers_to_members pragma in your source file as an alternative to using the /vmx compiler options or the inheritance keywords.
The pointer-declaration argument specifies whether you have declared a pointer to a member before or after the associated function definition. The pointer-declaration argument is one of the following two symbols:
Argument |
Comments |
|---|---|
full_generality |
Generates safe, sometimes nonoptimal code. You use full_generality if any pointer to a member is declared before the associated class definition. This argument always uses the pointer representation specified by the most-general-representation argument. Equivalent to /vmg. |
best_case |
Generates safe, optimal code using best-case representation for all pointers to members. Requires defining the class before declaring a pointer to a member of the class. The default is best_case. |
The most-general-representation argument specifies the smallest pointer representation that the compiler can safely use to reference any pointer to a member of a class in a translation unit. The argument can be one of the following:
Argument |
Comments |
|---|---|
single_inheritance |
The most general representation is single-inheritance, pointer to a member function. Causes an error if the inheritance model of a class definition for which a pointer to a member is declared is ever either multiple or virtual. |
multiple_inheritance |
The most general representation is multiple-inheritance, pointer to a member function. Causes an error if the inheritance model of a class definition for which a pointer to a member is declared is virtual. |
virtual_inheritance |
The most general representation is virtual-inheritance, pointer to a member function. Never causes an error. This is the default argument when #pragma pointers_to_members(full_generality) is used. |
Warning
We advise you to put the pointers_to_members pragma only in the source code file that you want to affect, and only after any #include directives. This practice lessens the risk that the pragma will affect other files, and that you will accidently specify multiple definitions for the same variable, function, or class name.
Example
// Specify single-inheritance only
#pragma pointers_to_members( full_generality, single_inheritance )