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> Unreal Engine API Reference > Runtime > Core > Misc > TVariant

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TVariant

A type-safe union based loosely on std::variant.

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Inheritance Hierarchy

TVariantStorage

TVariant

References

Module	Core
Header	/Engine/Source/Runtime/Core/Public/Misc/TVariant.h
Include	#include "Misc/TVariant.h"

Syntax

template<typename T, typename... Ts>
class TVariant : private UE4Variant_Details::TVariantStorage< T, Ts... >

Remarks

A type-safe union based loosely on std::variant. This flavor of variant requires that all the types in the declaring template parameter pack be unique. Attempting to use the value of a Get() when the underlying type is different leads to undefined behavior.

Constructors

	Name	Description
	TVariant()	Default initialize the TVariant to the first type in the parameter pack
	TVariant ( const TVariant& Other )	Copy construct the variant from another variant of the same type
	TVariant ( TVariant&& Other )	Move construct the variant from another variant of the same type
	TVariant ( TInPlaceType< U >&&, TArgs&&... Args )	Perform in-place construction of a type into the variant

Destructors

	Name	Description
	~TVariant()	Destruct the underlying type (if appropriate)

Functions

	Name	Description
void	Emplace ( TArgs&&... Args )	Set a specifically-typed value into the variant using in-place construction
U &	Get()	Get a reference to the held value.
const U &	Get()	Get a reference to the held value.
SIZE_T	GetIndex()	Returns the currently held type's index into the template parameter pack
constexpr SI...	IndexOfType()	Lookup the index of a type in the template parameter pack at compile time.
bool	IsType()	Determine if the variant holds the specific type
void	Set ( typename TIdentity< U >::Type&& Va... )	Set a specifically-typed value into the variant
void	Set ( const typename TIdentity< U >::Type... )	Set a specifically-typed value into the variant
U *	TryGet()	Get a pointer to the held value if the held type is the same as the one specified
const U *...	TryGet()	Get a pointer to the held value if the held type is the same as the one specified

Operators

		Name	Description
	TVariant &	operator= ( TVariant&& Other )	Move assign a variant from another variant of the same type
	TVariant &	operator= ( const TVariant& Other )	Copy assign a variant from another variant of the same type

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