BloombergLP::bdlb::VariantImp

This class provides the implementation of Variant (except for the creators) given a list of template parameter TYPES.

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.

Assign the type and value of rhs to this object.

Assign the type and value of rhs to this object.

Assign the specified TYPE value to this object.

Assign the specified TYPE value to this object.

Apply visitor to the held value of this modifiable variant.

Apply the specified visitor to this modifiable variant by passing the value this variant currently holds to the visitor object's operator().

Apply visitor to the held value and return its result.

Apply visitor to the held value of this variant.

Apply visitor to the held value of this modifiable variant.

Apply the specified visitor to this modifiable variant by passing the value this variant currently holds to the visitor object's operator().

Apply visitor to the held value and return its result.

Apply visitor to the held value of this variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held value and return RET_TYPE.

Same as the preceding overload, but for a const visitor.

Apply visitor to the held value and return RET_TYPE.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this variant.

Apply visitor to the held TYPE value of this variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this variant.

Apply visitor to the held TYPE value of this variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this variant.

Same as the preceding overload, but for a const visitor.

Apply visitor to the held TYPE value of this variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held value and return RET_TYPE.

Apply visitor to the held value of this variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held TYPE value of this modifiable variant.

Apply visitor to the held value and return its result.

Apply visitor to the held value of this variant.

Apply visitor to the held alternative without validity checks.

Apply visitor to the held value and return RET_TYPE.

Apply a const visitor to the held alternative without checks.

Same as the preceding overload, but for a const visitor.

Assign the specified TYPE value to this object.

Assign the specified TYPE value to this object.

Assign value converted to TYPE to this object.

DEPRECATED: Do not use.

bdexStreamOut

DEPRECATED: Do not use.

createInPlace

Emplace a TYPE instance constructed from arguments.

Return whether this variant currently holds a TYPE value.

Return whether this variant currently holds no value.

maxSupportedBdexVersion

DEPRECATED: Do not use.

Format this object to the specified output stream.

Destroy the current value held by this variant (if any), and reset this variant to the unset state.

Swap the value of this object with other.

Return a modifiable reference to the held TYPE value.

Return a non‐modifiable reference to the held TYPE value.

Return the 1‐based index of the held type, or 0 if unset.

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

Return whether lhs and rhs do not have the same value.

Grant the equality comparison operator access to this class's private members.

Return whether lhs and rhs have the same value.

Swap the values of the specified a and b objects.

Derived Classes

Name

Description

Discriminated union that holds a value of one of up to 20 alternative types.

Fixed‐arity specialization of Variant for 10 types.

Fixed‐arity specialization of Variant for 11 types.

Fixed‐arity specialization of Variant for 12 types.

Fixed‐arity specialization of Variant for 13 types.

Fixed‐arity specialization of Variant for 14 types.

Fixed‐arity specialization of Variant for 15 types.

Fixed‐arity specialization of Variant for 16 types.

Fixed‐arity specialization of Variant for 17 types.

Fixed‐arity specialization of Variant for 18 types.

Fixed‐arity specialization of Variant for 19 types.

Fixed‐arity specialization of Variant for 2 types.

Fixed‐arity specialization of Variant for 3 types.

Fixed‐arity specialization of Variant for 4 types.

Fixed‐arity specialization of Variant for 5 types.

Fixed‐arity specialization of Variant for 6 types.

Fixed‐arity specialization of Variant for 7 types.

Fixed‐arity specialization of Variant for 8 types.

Fixed‐arity specialization of Variant for 9 types.

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