BloombergLP::bdlb::VariantImp

Synopsis

Declared in <bdlb_variant.h>

template<class TYPES>
class VariantImp
    : public VariantImp_Traits<TYPES>::BaseType

Description

More generally, if each of the types in the list of TYPES is value semantic, then this class also supports a complete set of value semantic operations, including copy construction, assignment, equality comparison, and ostream printing. A precise operational definition of when two instances have the same value can be found in the description of operator== for the class. This class is exception neutral with no guarantee of rollback: if an exception is thrown during the invocation of a method on a pre-existing instance, the object is left in a valid state, but its value is undefined. In no event is memory leaked. Finally, aliasing (e.g., using all or part of an object as both source and destination) is supported in all cases.

If any of the types in the list of TYPES does not support operator==, or any of the value-semantic operations mentioned above, then this variant also does not support that operation and attempts to invoke it will trigger a compilation diagnostic.

Base Classes

Name	Description
`VariantImp_Traits<TYPES>::BaseType`

Member Functions

Name	Description
`VariantImp` [constructor]	Create a variant object in the unset state that uses the currently installed default allocator to supply memory.
`VariantImp` [constructor]	Create a variant by moving from `original`.
`VariantImp` [constructor]	Create a variant from `valueOrAllocator`.
`VariantImp` [constructor]	Create a variant by moving from the specified `value`.
`VariantImp` [constructor]	Create a variant holding `value` using `basicAllocator`.
`VariantImp` [constructor]	Create a variant by moving from `original` using `basicAllocator`.
`VariantImp` [constructor]	Create a variant with the type and value of `original`.
`VariantImp` [constructor]	Create a variant holding `value` using `basicAllocator`.
`~VariantImp` [destructor]	Destroy this variant object, invoking the destructor of the type of object contained (if any) on the value of that type.
`operator=`	Assign the type and value of `rhs` to this object.
`operator=`	Assign the type and value of `rhs` to this object.
`operator=`	Assign the specified `TYPE` `value` to this object.
`operator=`	Assign the specified `TYPE` `value` to this object.
`apply`	Apply `visitor` to the held value of this modifiable variant.
`apply`	Apply the specified `visitor` to this modifiable variant by passing the value this variant currently holds to the `visitor` object's `operator()`.
`apply`	Apply `visitor` to the held value and return its result.
`apply`	Apply `visitor` to the held value of this variant.
`apply`	Apply `visitor` to the held value of this modifiable variant.
`apply`	Apply the specified `visitor` to this modifiable variant by passing the value this variant currently holds to the `visitor` object's `operator()`.
`apply`	Apply `visitor` to the held value and return its result.
`apply`	Apply `visitor` to the held value of this variant.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held value and return `RET_TYPE`.
`apply`	Same as the preceding overload, but for a `const` visitor.
`apply`	Apply `visitor` to the held value and return `RET_TYPE`.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`apply`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`apply`	Same as the preceding overload, but for a `const` visitor.
`apply`	Apply `visitor` to the held `TYPE` value of this variant.
`applyRaw`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`applyRaw`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`applyRaw`	Apply `visitor` to the held value and return `RET_TYPE`.
`applyRaw`	Apply `visitor` to the held value of this variant.
`applyRaw`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`applyRaw`	Apply `visitor` to the held `TYPE` value of this modifiable variant.
`applyRaw`	Apply `visitor` to the held value and return its result.
`applyRaw`	Apply `visitor` to the held value of this variant.
`applyRaw`	Apply `visitor` to the held alternative without validity checks.
`applyRaw`	Apply `visitor` to the held value and return `RET_TYPE`.
`applyRaw`	Apply a const `visitor` to the held alternative without checks.
`applyRaw`	Same as the preceding overload, but for a `const` visitor.
`assign`	Assign the specified `TYPE` `value` to this object.
`assign`	Assign the specified `TYPE` `value` to this object.
`assignTo`	Assign `value` converted to `TYPE` to this object.
`bdexStreamIn`	DEPRECATED: Do not use.
`bdexStreamOut`	DEPRECATED: Do not use.
`createInPlace`	Emplace a `TYPE` instance constructed from `arguments`.
`is`	Return whether this variant currently holds a `TYPE` value.
`isUnset`	Return whether this variant currently holds no value.
`maxSupportedBdexVersion`	DEPRECATED: Do not use.
`print`	Format this object to the specified output `stream`.
`reset`	Destroy the current value held by this variant (if any), and reset this variant to the unset state.
`swap`	Swap the value of this object with `other`.
`the`	Return a modifiable reference to the held `TYPE` value.
`the`	Return a non-modifiable reference to the held `TYPE` value.
`typeIndex`	Return the 1-based index of the held type, or 0 if unset.
`typeInfo`	Return `typeid(void)`.
`operator BloombergLP::bslmf::NestedTraitDeclaration<VariantImp, HasPrintMethod>`	Nested trait declaration for `bdlb::HasPrintMethod`.
`operator BloombergLP::bslmf::NestedTraitDeclaration<VariantImp, IsBitwiseCopyable, Traits::k_VARIANT_IS_BITWISE_COPYABLE>`	Nested trait declaration for `bslmf::IsBitwiseCopyable`.
`operator BloombergLP::bslmf::NestedTraitDeclaration<VariantImp, IsBitwiseMoveable, Traits::k_VARIANT_IS_BITWISE_MOVEABLE>`	Nested trait declaration for `bslmf::IsBitwiseMoveable`.
`operator BloombergLP::bslmf::NestedTraitDeclaration<VariantImp, UsesBslmaAllocator, Traits::k_VARIANT_USES_BSLMA_ALLOCATOR>`	Nested trait declaration for `bslma::UsesBslmaAllocator`.

Non-Member Functions

Name	Description
`operator!=`	Return whether `lhs` and `rhs` do not have the same value.
`operator==`	Grant the equality comparison operator access to this class's private members.
`operator==`	Return whether `lhs` and `rhs` have the same value.
`swap`	Swap the values of the specified `a` and `b` objects.

Derived Classes

Name	Description
`Variant`	Discriminated union that holds a value of one of up to 20 alternative types.
`Variant10`	Fixed-arity specialization of `Variant` for 10 types.
`Variant11`	Fixed-arity specialization of `Variant` for 11 types.
`Variant12`	Fixed-arity specialization of `Variant` for 12 types.
`Variant13`	Fixed-arity specialization of `Variant` for 13 types.
`Variant14`	Fixed-arity specialization of `Variant` for 14 types.
`Variant15`	Fixed-arity specialization of `Variant` for 15 types.
`Variant16`	Fixed-arity specialization of `Variant` for 16 types.
`Variant17`	Fixed-arity specialization of `Variant` for 17 types.
`Variant18`	Fixed-arity specialization of `Variant` for 18 types.
`Variant19`	Fixed-arity specialization of `Variant` for 19 types.
`Variant2`	Fixed-arity specialization of `Variant` for 2 types.
`Variant3`	Fixed-arity specialization of `Variant` for 3 types.
`Variant4`	Fixed-arity specialization of `Variant` for 4 types.
`Variant5`	Fixed-arity specialization of `Variant` for 5 types.
`Variant6`	Fixed-arity specialization of `Variant` for 6 types.
`Variant7`	Fixed-arity specialization of `Variant` for 7 types.
`Variant8`	Fixed-arity specialization of `Variant` for 8 types.
`Variant9`	Fixed-arity specialization of `Variant` for 9 types.