IDebugHostType3::IsTypedef method (dbgmodel.h)

The IsTypedef method is the only method capable of seeing whether a type is a typedef. The GetTypeKind method will behave as if called on the underlying type.

Syntax

HRESULT IsTypedef(
  bool *isTypedef
);

Parameters

isTypedef

Will return true if the type symbol is a typedef and false if it is not.

Return value

This method returns HRESULT.

Remarks

Sample Code

ComPtr<IDebugHostType> spType; /* get a type for a typedef (only FindTypeByName 
                                  since the compiler usually only emits base types 
                                  in the symbols for data) */

ComPtr<IDebugHostType3> spType3;
if (SUCCEEDED(spType.As(&spType3)))
{
    bool isTypeDef;
    if (SUCCEEDED(spType3->IsTypedef(&isTypeDef)))
    {
        // isTypeDef indicates whether the type is a typedef.
    }
}

Any type which is a typedef will behave as if the type is the final type underlying the typedef. This means that methods such as GetTypeKind will not indicate that the type is a typedef. Likewise, the GetBaseType method will not return the type the definition refers to. They will instead indicate behave as if they were called on the final definition underlying the typedef. As an example:

typedef MYSTRUCT *PMYSTRUCT;
typedef PMYSTRUCT PTRMYSTRUCT;

An IDebugHostType for 'either PMYSTRUCT or PTRMYSTRUCT will report the following information:

• The GetTypeKind method will return TypePointer. The final underlying type MYSTRUCT * is indeed a pointer.

• The GetBaseType method will return a type for MYSTRUCT. The underlying type of MYSTRUCT * is MYSTRUCT.

The only difference here is how the typedef specific methods on IDebugHostType3 behave. Those methods are:

STDMETHOD(IsTypedef)(_Out_ bool* isTypedef) PURE;

STDMETHOD(GetTypedefBaseType)(_Out_ IDebugHostType3** baseType) PURE;

STDMETHOD(GetTypedefFinalBaseType)(_Out_ IDebugHostType3** finalBaseType) PURE;

In this example:

• The IsTypedef method will return true for both PMYSTRUCT and PTRMYSTRUCT
• The GetTypedefBaseType method will return MYSTRUCT * for PMYSTRUCT and PMYSTRUCT for PTRMYSTRUCT
• The GetTypedefFinalBaseType method will return MYSTRUCT * for both types

Requirements

Requirement	Value
Header	dbgmodel.h

See also

IDebugHostType3 interface