Variant<T extends Object?> extension type com

A Dart wrapper around the COM VARIANT structure.

VARIANT is a tagged union used extensively in COM and Automation APIs to transport values whose type is determined at runtime.

This wrapper provides:

Safe allocation and cleanup
Dart-friendly accessors
Type-checked reads via the generic parameter T
Strongly-typed factory constructors for common VARIANT kinds

Memory for the underlying VARIANT is allocated natively. Any contained resources (e.g., BSTR, interface pointers) are owned by the VARIANT. Call free when the Variant is no longer needed to avoid leaks.

The generic parameter T represents the expected Dart view of the stored value. It is not used to determine the underlying VARIANT type. Instead, it is validated at read time.

A mismatch between the actual vt and T results in a StateError.

on

Pointer<VARIANT>

Implemented types

Pointer<VARIANT>

Implementers

Constructors

Variant(): Creates a new empty Variant.
factory
Variant.from(T value): Creates a new Variant initialized with the provided value.
factory
Variant.fromPointer(Pointer<VARIANT> ptr): Creates a Variant from an existing VARIANT pointer.
factory

Properties

address → int: Access to the raw pointer value. On 32-bit systems, the upper 32-bits of the result are 0.
no setterinherited
boolVal ↔ bool: getter/setter pair
bstrVal ↔ BSTR: getter/setter pair
bVal ↔ int: getter/setter pair
byref ↔ Pointer<NativeType>: getter/setter pair
cVal ↔ CHAR: getter/setter pair
cyVal ↔ CY: getter/setter pair
date ↔ double: getter/setter pair
dblVal ↔ double: getter/setter pair
decVal ↔ DECIMAL: getter/setter pair
fltVal ↔ double: getter/setter pair
hashCode → int: The hash code for a Pointer only depends on its address.
no setterinherited
intVal ↔ int: getter/setter pair
isEmpty → bool: Whether this VARIANT is empty (VT_EMPTY).
no setter
isNull → bool: Whether this VARIANT represents a COM null (VT_NULL).
no setter
iVal ↔ int: getter/setter pair
llVal ↔ int: getter/setter pair
lVal ↔ int: getter/setter pair
parray ↔ Pointer<SAFEARRAY>: getter/setter pair
pboolVal ↔ Pointer<Int16>: getter/setter pair
pbstrVal ↔ Pointer<Pointer<Utf16>>: getter/setter pair
pbVal ↔ Pointer<Uint8>: getter/setter pair
pcVal ↔ PSTR: getter/setter pair
pcyVal ↔ Pointer<CY>: getter/setter pair
pdate ↔ Pointer<Double>: getter/setter pair
pdblVal ↔ Pointer<Double>: getter/setter pair
pdecVal ↔ Pointer<DECIMAL>: getter/setter pair
pdispVal ↔ IDispatch?: getter/setter pair
pfltVal ↔ Pointer<Float>: getter/setter pair
pintVal ↔ Pointer<Int32>: getter/setter pair
piVal ↔ Pointer<Int16>: getter/setter pair
pllVal ↔ Pointer<Int64>: getter/setter pair
plVal ↔ Pointer<Int32>: getter/setter pair
pparray ↔ Pointer<Pointer<SAFEARRAY>>: getter/setter pair
ppdispVal ↔ Pointer<VTablePointer>: getter/setter pair
ppunkVal ↔ Pointer<VTablePointer>: getter/setter pair
pscode ↔ Pointer<Int32>: getter/setter pair
puintVal ↔ Pointer<Uint32>: getter/setter pair
puiVal ↔ Pointer<Uint16>: getter/setter pair
pullVal ↔ Pointer<Uint64>: getter/setter pair
pulVal ↔ Pointer<Uint32>: getter/setter pair
punkVal ↔ IUnknown?: getter/setter pair
pvarVal ↔ Pointer<VARIANT>: getter/setter pair
ref ↔ VARIANT: Provides access to the underlying VARIANT structure.
getter/setter pair
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
scode ↔ int: getter/setter pair
uintVal ↔ int: getter/setter pair
uiVal ↔ int: getter/setter pair
ullVal ↔ int: getter/setter pair
ulVal ↔ int: getter/setter pair
value ↔ T: Gets or sets the Dart value represented by this VARIANT.
getter/setter pair
vt ↔ VARENUM: The vt field of the VARIANT, representing the type of data stored.
getter/setter pair

Methods

cast<U extends NativeType>() → Pointer<U>: Reinterprets the address of this pointer as the address of a U.
inherited
copy() → Variant<T>: Creates a deep copy of this Variant.
free() → void: Releases all resources held by this Variant and frees its memory.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toString() → String: A string representation of this object.
inherited
tryGet<R extends Object?>() → R?: Attempts to read the value stored in this VARIANT as type R.

Operators

operator ==(Object other) → bool: Equality for Pointers only depends on their address.
inherited

Static Methods

bool$(bool value) → VariantBool: Creates a Variant holding a VARIANT_BOOL value.
bstr(String value) → VariantBSTR: Creates a Variant holding a BSTR value.
dispatch(IDispatch value) → VariantDispatch: Creates a Variant holding an IDispatch value.
dispatchByRef(Pointer<VTablePointer> value) → VariantDispatchByRef: Creates a Variant holding a reference to an IDispatch value.
double$(double value) → VariantDouble: Creates a Variant holding a Double value.
float(double value) → VariantFloat: Creates a Variant holding a Float value.
int16(int value) → VariantInt16: Creates a Variant holding an Int16 value.
int32(int value) → VariantInt32: Creates a Variant holding an Int32 value.
int64(int value) → VariantInt64: Creates a Variant holding an Int64 value.
int8(int value) → VariantInt8: Creates a Variant holding an Int8 value.
uint16(int value) → VariantUint16: Creates a Variant holding a Uint16 value.
uint32(int value) → VariantUint32: Creates a Variant holding a Uint32 value.
uint64(int value) → VariantUint64: Creates a Variant holding a Uint64 value.
uint8(int value) → VariantUint8: Creates a Variant holding a Uint8 value.
unknown(IUnknown value) → VariantUnknown: Creates a Variant holding an IUnknown value.
unknownByRef(Pointer<VTablePointer> value) → VariantUnknownByRef: Creates a Variant holding a reference to an IUnknown value.