19.3.1 Basic Automation Types
Table 19-1 lists the basic data types supported by Automation. The table contains fewer data types than those allowed by ODL
because not all types recognized by ODL can be handled by the marshaling of IDispatch interfaces and by the implementation
of ITypeInfo::Invoke. Arguments and return values of operations and properties are restricted to these basic types.
Table 19-1 Automation Basic Types
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| Type |
Description |
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| boolean |
True = -1, False = 0. |
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| double |
64-bit IEEE floating-point number. |
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| float |
32-bit IEEE floating-point number. |
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| long |
32-bit signed integer. |
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| short |
16-bit signed integer. |
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| void |
Allowed only as a return type for a function, or in a function parameter list to indicate no parameters. |
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| BSTR |
Length-prefixed string. Prefix is an integer. |
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| Type |
Description |
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| CURRENCY |
8-byte fixed-point number. |
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| DATE |
64-bit floating-point fractional number of days since December 30, 1899. |
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| SCODE |
Built-in error type. In Win16, does not include additional data contained in an HRESULT. In Win32, identical to HRESULT. |
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| IDispatch * |
Pointer to IDispatch interface. From the viewpoint of the mapping, an IDispatch pointer parameter is an object reference.
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| IUnknown * |
Pointer to IUnknown interface. (Any OLE interface can be represented by its IUnknown interface.) |
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The formal mapping of CORBA types to Automation types is shown in Table 19-2. Table 19-2 OMG CORBA to Automation Data Type
Mappings
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| CORBA Type |
OLE Automation Type |
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| boolean |
VARIANT_BOOL |
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| char |
UI1 |
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| double |
double |
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| float |
float |
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| long |
long |
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| octet |
short |
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| short |
short |
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| unsigned long |
long |
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| unsigned short |
long |
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