Data Type Conversion Functions
The following low-level functions convert variant data types. Higher-level variant manipulation functions (such as VariantChangeType) use these functions, but they can also be called directly.
Functions to convert to type char
| From type | Function |
|---|---|
| unsigned char | VarI1FromUI1 |
| unsigned short | VarI1FromUI2 |
| unsigned long | VarI1FromUI4 |
| ULONG64 | VarI1FromUI8 |
| short | VarI1FromI2 |
| long | VarI1FromI4 |
| LONG64 | VarI1FromI8 |
| float | VarI1FromR4 |
| double | VarI1FromR8 |
| CURRENCY | VarI1FromCy |
| DECIMAL | VarI1FromDec |
| DATE | VarI1FromDate |
| OLECHAR * | VarI1FromStr |
| IDispatch * | VarI1FromDisp |
| BOOL | VarI1FromBool |
Functions to convert to type unsigned char
| From type | Function |
|---|---|
| unsigned short | VarUI1FromUI2 |
| unsigned long | VarUI1FromUI4 |
| ULONG64 | VarI1FromUI8 |
| char | VarUI1FromI1 |
| short | VarUI1FromI2 |
| long | VarUI1FromI4 |
| LONG64 | VarUI1FromI8 |
| float | VarUI1FromR4 |
| double | VarUI1FromR8 |
| CURRENCY | VarUI1FromCy |
| DECIMAL | VarUI1FromDec |
| DATE | VarUI1FromDate |
| OLECHAR * | VarUI1FromStr |
| IDispatch * | VarUI1FromDisp |
| BOOL | VarUI1FromBool |
Functions to convert to type short
| From type | Function |
|---|---|
| unsigned char | VarI2FromUI1 |
| unsigned short | VarI2FromUI2 |
| unsigned long | VarI2FromUI4 |
| ULONG64 | VarI2FromUI8 |
| char | VarI2FromI1 |
| long | VarI2FromI4 |
| LONG64 | VarI2FromI8 |
| float | VarI2FromR4 |
| double | VarI2FromR8 |
| CURRENCY | VarI2FromCy |
| DECIMAL | VarI2FromDec |
| DATE | VarI2FromDate |
| OLECHAR * | VarI2FromStr |
| IDispatch * | VarI2FromDisp |
| BOOL | VarI2FromBool |
Functions to convert to type unsigned short
| From type | Function |
|---|---|
| char | VarUI2FromI1 |
| short | VarUI2FromI2 |
| long | VarUI2FromI4 |
| LONG64 | VarUI2FromI8 |
| unsigned char | VarUI2FromUI1 |
| unsigned long | VarUI2FromUI4 |
| LONG64 | VarUI2FromUI8 |
| float | VarUI2FromR4 |
| double | VarUI2FromR8 |
| CURRENCY | VarUI2FromCy |
| DECIMAL | VarUI2FromDec |
| DATE | VarUI2FromDate |
| OLECHAR * | VarUI2FromStr |
| IDispatch * | VarUI2FromDisp |
| BOOL | VarUI2FromBool |
Functions to convert to type long
| From type | Function |
|---|---|
| unsigned short | VarI4FromUI2 |
| unsigned long | VarI4FromUI4 |
| ULONG64 | VarI4FromUI8 |
| char | VarI4FromI1 |
| unsigned char | VarI4FromUI1 |
| short | VarI4FromI2 |
| LONG64 | VarI4FromI8 |
| float | VarI4FromR4 |
| double | VarI4FromR8 |
| CURRENCY | VarI4FromCy |
| DECIMAL | VarI4FromDec |
| DATE | VarI4FromDate |
| OLECHAR * | VarI4FromStr |
| IDispatch * | VarI4FromDisp |
| BOOL | VarI4FromBool |
| INT | VarI4FromInt |
Functions to convert to type unsigned long
| From type | Function |
|---|---|
| unsigned short | VarUI4FromUI2 |
| char | VarUI4FromI1 |
| short | VarUI4FromI2 |
| unsigned char | VarUI4FromUI1 |
| ULONG64 | VarUI4FromUI8 |
| long | VarUI4FromI4 |
| LONG64 | VarUI4FromI8 |
| float | VarUI4FromR4 |
| double | VarUI4FromR8 |
| CURRENCY | VarUI4FromCy |
| DECIMAL | VarUI4FromDec |
| DATE | VarUI4FromDate |
| OLECHAR * | VarUI4FromStr |
| IDispatch * | VarUI4FromDisp |
| BOOL | VarUI4FromBool |
Functions to convert to type float
| From type | Function |
|---|---|
| unsigned short | VarR4FromUI2 |
| unsigned long | VarR4FromUI4 |
| ULONG64 | VarR4FromUI8 |
| char | VarR4FromI1 |
| unsigned char | VarR4FromUI1 |
| short | VarR4FromI2 |
| long | VarR4FromI4 |
| LONG64 | VarR4FromI8 |
| double | VarR4FromR8 |
| CURRENCY | VarR4FromCy |
| DECIMAL | VarR4FromDec |
| DATE | VarR4FromDate |
| OLECHAR * | VarR4FromStr |
| IDispatch * | VarR4FromDisp |
| BOOL | VarR4FromBool |
Functions to convert to type double
| From type | Function |
|---|---|
| unsigned short | VarR8FromUI2 |
| unsigned long | VarR8FromUI4 |
| ULONG64 | VarR8FromUI8 |
| char | VarR8FromI1 |
| unsigned char | VarR8FromUI1 |
| short | VarR8FromI2 |
| long | VarR8FromI4 |
| LONG64 | VarR8FromI8 |
| float | VarR8FromR4 |
| CURRENCY | VarR8FromCy |
| DECIMAL | VarR8FromDec |
| DATE | VarR8FromDate |
| OLECHAR * | VarR8FromStr |
| IDispatch * | VarR8FromDisp |
| BOOL | VarR8FromBool |
Functions to convert to type DATE
| From type | Function |
|---|---|
| unsigned short | VarDateFromUI2 |
| unsigned long | VarDateFromUI4 |
| ULONG64 | VarDateFromUI8 |
| char | VarDateFromI1 |
| unsigned char | VarDateFromUI1 |
| short | VarDateFromI2 |
| long | VarDateFromI4 |
| LONG64 | VarDateFromI8 |
| float | VarDateFromR4 |
| double | VarDateFromR8 |
| CURRENCY | VarDateFromCy |
| DECIMAL | VarDateFromDec |
| OLECHAR * | VarDateFromStr |
| IDispatch * | VarDateFromDisp |
| BOOL | VarDateFromBool |
Functions to convert to type CURRENCY
| From type | Function |
|---|---|
| unsigned short | VarCyFromUI2 |
| unsigned long | VarCyFromUI4 |
| ULONG64 | VarCyFromUI8 |
| char | VarCyFromI1 |
| unsigned char | VarCyFromUI1 |
| short | VarCyFromI2 |
| long | VarCyFromI4 |
| LONG64 | VarCyFromI8 |
| float | VarCyFromR4 |
| double | VarCyFromR8 |
| DECIMAL | VarCyFromDec |
| DATE | VarCyFromDate |
| OLECHAR * | VarCyFromStr |
| IDispatch * | VarCyFromDisp |
| BOOL | VarCyFromBool |
Functions to convert to type BSTR
| From type | Function |
|---|---|
| unsigned short | VarBstrFromUI2 |
| unsigned long | VarBstrFromUI4 |
| ULONG64 | VarBstrFromUI8 |
| char | VarBstrFromI1 |
| unsigned char | VarBstrFromUI1 |
| short | VarBstrFromI2 |
| long | VarBstrFromI4 |
| LONG64 | VarBstrFromI8 |
| float | VarBstrFromR4 |
| double | VarBstrFromR8 |
| CURRENCY | VarBstrFromCy |
| DECIMAL | VarBstrFromDec |
| DATE | VarBstrFromDate |
| IDispatch * | VarBstrFromDisp |
| BOOL | VarBstrFromBool |
Functions to convert to type BOOL
| From type | Function |
|---|---|
| unsigned short | VarBoolFromUI2 |
| unsigned long | VarBoolFromUI4 |
| ULONG64 | VarBoolFromUI8 |
| char | VarBoolFromI1 |
| unsigned char | VarBoolFromUI1 |
| short | VarBoolFromI2 |
| long | VarBoolFromI4 |
| LONG64 | VarBoolFromI8 |
| float | VarBoolFromR4 |
| double | VarBoolFromR8 |
| CURRENCY | VarBoolFromCy |
| DECIMAL | VarBoolFromDec |
| DATE | VarBoolFromDate |
| OLECHAR * | VarBoolFromStr |
| IDispatch * | VarBoolFromDisp |
Functions to convert to type DECIMAL
| From type | Function |
|---|---|
| unsigned short | VarDecFromUI2 |
| unsigned long | VarDecFromUI4 |
| ULONG64 | VarDecFromUI8 |
| char | VarDecFromI1 |
| usigned char | VarDecFromUI1 |
| short | VarDecFromI2 |
| long | VarDecFromI4 |
| LONG64 | VarDecFromI8 |
| float | VarDecFromR4 |
| double | VarDecFromR8 |
| CURRENCY | VarDecFromCy |
| DATE | VarDecFromDate |
| OLECHAR * | VarDecFromStr |
| IDispatch * | VarDecFromDisp |
| BOOL | VarDecFromBool |
Note
If these functions are passed NULL pointers, there will be an access violation and the program will crash. It is your responsibility to protect these functions against NULL pointers.
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