parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload > Class Template Reference

Adapter that lets a parent struct's payload field descriptor be reused by a derived struct. More...

#include <struct.h>

Inheritance diagram for parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >:

Collaboration diagram for parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >:

Public Member Functions
	InheritedFieldDescriptor (std::shared_ptr< IPayloadFieldDescriptor< ParentPayload > > inner)
	Wrap a parent payload field descriptor.
std::string_view	key () const override
	JSON key under which this field appears in "v".
std::string_view	kind () const override
	Cell kind id for the field's value type.
DisplayInfo	display_info () const override
	Display info for this field.
bool	is_required () const override
	Whether the field must be present on deserialization.
json_t	to_json () const override
	Serialize the field descriptor itself.
DisplayInfo &	mutable_display_info () override
	Mutable access to this field's display info — used by FieldsBuilder.
void	set_required (const bool r) override
	Override the field's required flag.
void	to_json_into (json_t &v_obj, DerivedPayload const &p) const override
	Serialize this field from p into the value object v_obj.
void	from_json_into (json_t const &field_json, DerivedPayload &p, ParcelRegistry const &reg) const override
	Deserialize this field from field_json into p.
void	to_string_into (std::string &out, DerivedPayload const &p) const override
	Append key: value for this field to the rendered string.
std::partial_ordering	compare (DerivedPayload const &a, DerivedPayload const &b) const override
	Three-way compare this field across two payload instances.

Detailed Description

template<typename DerivedPayload, typename ParentPayload>
class parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >

Adapter that lets a parent struct's payload field descriptor be reused by a derived struct.

Holds a shared_ptr<IPayloadFieldDescriptor<ParentPayload>> and forwards every call after static_cast-ing the derived payload reference to the parent payload reference. The cast is sound because extend<> constrains DerivedPayload to derive from ParentPayload.

Template Parameters

DerivedPayload	The struct type using the inherited field.
ParentPayload	The struct type that originally declared the field.

Constructor & Destructor Documentation

InheritedFieldDescriptor()

template<typename DerivedPayload , typename ParentPayload >

parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::InheritedFieldDescriptor ( std::shared_ptr< IPayloadFieldDescriptor< ParentPayload > >  inner )

inlineexplicit

Wrap a parent payload field descriptor.

Parameters

inner

Parent descriptor to forward to.

Member Function Documentation

compare()

template<typename DerivedPayload , typename ParentPayload >

std::partial_ordering parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::compare ( DerivedPayload const &  a, DerivedPayload const &  b  ) const

inlineoverridevirtual

Three-way compare this field across two payload instances.

StructCell::compare walks fields in declaration order and short- circuits on the first non-equal result; ignores display info. Optional fields follow std::optional's <=>: absent < present, both absent is equal.

Implements parcel::IPayloadFieldDescriptor< DerivedPayload >.

from_json_into()

template<typename DerivedPayload , typename ParentPayload >

void parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::from_json_into ( json_t const &  field_json, DerivedPayload &  p, ParcelRegistry const &  reg  ) const

inlineoverridevirtual

Deserialize this field from field_json into p.

Parameters

field_json	JSON value for this field (already a wrapped cell).
p	Payload instance to write into.
reg	Registry forwarded to nested cell deserializers.

Implements parcel::IPayloadFieldDescriptor< DerivedPayload >.

to_json()

template<typename DerivedPayload , typename ParentPayload >

json_t parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::to_json ( ) const

inlineoverridevirtual

Serialize the field descriptor itself.

Returns

JSON object with key, kind, display_info, required.

Implements parcel::IFieldDescriptor.

to_json_into()

template<typename DerivedPayload , typename ParentPayload >

void parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::to_json_into ( json_t &  v_obj, DerivedPayload const &  p  ) const

inlineoverridevirtual

Serialize this field from p into the value object v_obj.

Parameters

v_obj	Target JSON object (the "v" block of the cell).
p	Payload instance to read from.

Implements parcel::IPayloadFieldDescriptor< DerivedPayload >.

to_string_into()

template<typename DerivedPayload , typename ParentPayload >

void parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >::to_string_into ( std::string &  out, DerivedPayload const &  p  ) const

inlineoverridevirtual

Append key: value for this field to the rendered string.

Parameters

out	String buffer to append to.
p	Payload instance to read from.

Implements parcel::IPayloadFieldDescriptor< DerivedPayload >.

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

• include/parcel/struct.h