lsst.afw  19.0.0-23-g9b026a6e0
Public Member Functions | Related Functions | List of all members
lsst::afw::typehandling::PolymorphicValue Class Referencefinal

Container that passes Storable objects by value while preserving type. More...

#include <PolymorphicValue.h>

Public Member Functions

 PolymorphicValue (Storable const &value)
 Create a new object containing a copy of a Storable. More...
 
 ~PolymorphicValue () noexcept
 
bool empty () const noexcept
 Check whether this object contains a Storable. More...
 
std::size_t hash_value () const
 Return a hash of this object (optional operation). More...
 
 PolymorphicValue (PolymorphicValue const &other)
 Try to copy a PolymorphicValue. More...
 
 PolymorphicValue (PolymorphicValue &&other) noexcept
 Try to copy a PolymorphicValue. More...
 
PolymorphicValueoperator= (PolymorphicValue const &other)
 Try to assign a PolymorphicValue. More...
 
PolymorphicValueoperator= (PolymorphicValue &&other) noexcept
 Try to assign a PolymorphicValue. More...
 
void swap (PolymorphicValue &other) noexcept
 Exchange the contents of this container and another. More...
 
 operator Storable & ()
 Return a reference to the internal Storable, if one exists. More...
 
 operator Storable const & () const
 Return a reference to the internal Storable, if one exists. More...
 
Storableget ()
 Return a reference to the internal Storable, if one exists. More...
 
Storable const & get () const
 Return a reference to the internal Storable, if one exists. More...
 
bool operator== (PolymorphicValue const &other) const noexcept
 Test whether the contained Storables are equal. More...
 
bool operator!= (PolymorphicValue const &other) const noexcept
 Test whether the contained Storables are equal. More...
 

Related Functions

(Note that these are not member functions.)

void swap (PolymorphicValue &lhs, PolymorphicValue &rhs) noexcept
 Swap specialization for PolymorphicValue. More...
 

Detailed Description

Container that passes Storable objects by value while preserving type.

This class is implicitly convertible to and from a reference to Storable, but behaves like a value: changing the internal Storable changes the object's state, and copying the object creates a new Storable.

Note
While a PolymorphicValue is always initialized with a Storable, it may become empty if it is the source of a move-construction or move-assignment. Conversion of an empty value to Storable& throws.

Definition at line 52 of file PolymorphicValue.h.

Constructor & Destructor Documentation

◆ PolymorphicValue() [1/3]

lsst::afw::typehandling::PolymorphicValue::PolymorphicValue ( Storable const &  value)

Create a new object containing a copy of a Storable.

Parameters
valuethe value to copy into a PolymorphicValue

Definition at line 33 of file PolymorphicValue.cc.

◆ ~PolymorphicValue()

lsst::afw::typehandling::PolymorphicValue::~PolymorphicValue ( )
defaultnoexcept

◆ PolymorphicValue() [2/3]

lsst::afw::typehandling::PolymorphicValue::PolymorphicValue ( PolymorphicValue const &  other)

Try to copy a PolymorphicValue.

Parameters
otherthe PolymorphicValue to copy.
Exceptions
UnsupportedOperationExceptionThrown if a copy is required and the object in other does not implement Storable::cloneStorable.

Definition at line 39 of file PolymorphicValue.cc.

◆ PolymorphicValue() [3/3]

lsst::afw::typehandling::PolymorphicValue::PolymorphicValue ( PolymorphicValue &&  other)
defaultnoexcept

Try to copy a PolymorphicValue.

Parameters
otherthe PolymorphicValue to copy.
Exceptions
UnsupportedOperationExceptionThrown if a copy is required and the object in other does not implement Storable::cloneStorable.

Member Function Documentation

◆ empty()

bool lsst::afw::typehandling::PolymorphicValue::empty ( ) const
noexcept

Check whether this object contains a Storable.

Returns
true if this object has no Storable, false otherwise

Definition at line 62 of file PolymorphicValue.cc.

◆ get() [1/2]

Storable & lsst::afw::typehandling::PolymorphicValue::get ( )

Return a reference to the internal Storable, if one exists.

Returns
a reference to the internal object
Exceptions
pex::exceptions::LogicErrorThrown if this object is empty.

Definition at line 66 of file PolymorphicValue.cc.

◆ get() [2/2]

Storable const & lsst::afw::typehandling::PolymorphicValue::get ( ) const

Return a reference to the internal Storable, if one exists.

Returns
a reference to the internal object
Exceptions
pex::exceptions::LogicErrorThrown if this object is empty.

Definition at line 70 of file PolymorphicValue.cc.

◆ hash_value()

std::size_t lsst::afw::typehandling::PolymorphicValue::hash_value ( ) const

Return a hash of this object (optional operation).

Exceptions
UnsupportedOperationExceptionThrown if the internal Storable is not hashable.

Definition at line 87 of file PolymorphicValue.cc.

◆ operator Storable &()

lsst::afw::typehandling::PolymorphicValue::operator Storable & ( )

Return a reference to the internal Storable, if one exists.

Returns
a reference to the internal object
Exceptions
pex::exceptions::LogicErrorThrown if this object is empty.

Definition at line 64 of file PolymorphicValue.cc.

◆ operator Storable const &()

lsst::afw::typehandling::PolymorphicValue::operator Storable const & ( ) const

Return a reference to the internal Storable, if one exists.

Returns
a reference to the internal object
Exceptions
pex::exceptions::LogicErrorThrown if this object is empty.

◆ operator!=()

bool lsst::afw::typehandling::PolymorphicValue::operator!= ( PolymorphicValue const &  other) const
inlinenoexcept

Test whether the contained Storables are equal.

Empty PolymorphicValues compare equal to each other and unequal to any non-empty PolymorphicValue.

Definition at line 130 of file PolymorphicValue.h.

◆ operator=() [1/2]

PolymorphicValue & lsst::afw::typehandling::PolymorphicValue::operator= ( PolymorphicValue &&  other)
noexcept

Try to assign a PolymorphicValue.

To preserve the run-time type of the object in other, this method swaps (and possibly copies) the Storables instead of relying on the Storable's operator=.

Parameters
otherthe PolymorphicValue to overwrite this value with.
Exceptions
UnsupportedOperationExceptionThrown if a copy is required and the object in other does not implement Storable::cloneStorable.

Definition at line 51 of file PolymorphicValue.cc.

◆ operator=() [2/2]

PolymorphicValue & lsst::afw::typehandling::PolymorphicValue::operator= ( PolymorphicValue const &  other)

Try to assign a PolymorphicValue.

To preserve the run-time type of the object in other, this method swaps (and possibly copies) the Storables instead of relying on the Storable's operator=.

Parameters
otherthe PolymorphicValue to overwrite this value with.
Exceptions
UnsupportedOperationExceptionThrown if a copy is required and the object in other does not implement Storable::cloneStorable.

Definition at line 43 of file PolymorphicValue.cc.

◆ operator==()

bool lsst::afw::typehandling::PolymorphicValue::operator== ( PolymorphicValue const &  other) const
noexcept

Test whether the contained Storables are equal.

Empty PolymorphicValues compare equal to each other and unequal to any non-empty PolymorphicValue.

Definition at line 78 of file PolymorphicValue.cc.

◆ swap()

void lsst::afw::typehandling::PolymorphicValue::swap ( PolymorphicValue other)
noexcept

Exchange the contents of this container and another.

Definition at line 57 of file PolymorphicValue.cc.

Friends And Related Function Documentation

◆ swap()

void swap ( PolymorphicValue lhs,
PolymorphicValue rhs 
)
related

Swap specialization for PolymorphicValue.

Definition at line 152 of file PolymorphicValue.h.


The documentation for this class was generated from the following files: