parcel::IPayloadFieldDescriptor< Payload > Struct Template Reference

Field-descriptor extension that knows how to read/write a specific Payload. More...

#include <struct.h>

Inheritance diagram for parcel::IPayloadFieldDescriptor< Payload >:

Collaboration diagram for parcel::IPayloadFieldDescriptor< Payload >:

Public Member Functions
virtual void	to_json_into (json_t &v_obj, Payload const &p) const =0
	Serialize this field from p into the value object v_obj.
virtual void	from_json_into (json_t const &field_json, Payload &p, ParcelRegistry const &reg) const =0
	Deserialize this field from field_json into p.
virtual void	to_string_into (std::string &out, Payload const &p) const =0
	Append key: value for this field to the rendered string.
virtual std::partial_ordering	compare (Payload const &a, Payload const &b) const =0
	Three-way compare this field across two payload instances.
virtual DisplayInfo &	mutable_display_info ()=0
	Mutable access to this field's display info — used by FieldsBuilder.
virtual void	set_required (bool r)=0
	Override the field's required flag.
Public Member Functions inherited from parcel::IFieldDescriptor
virtual std::string_view	key () const =0
	JSON key under which this field appears in "v".
virtual std::string_view	kind () const =0
	Cell kind id for the field's value type.
virtual DisplayInfo	display_info () const =0
	Display info for this field.
virtual bool	is_required () const =0
	Whether the field must be present on deserialization.
virtual json_t	to_json () const =0
	Serialize the field descriptor itself.

Detailed Description

template<typename Payload>
struct parcel::IPayloadFieldDescriptor< Payload >

Field-descriptor extension that knows how to read/write a specific Payload.

Refines IFieldDescriptor with hooks the StructCell machinery uses to project payload members in and out of JSON.

Template Parameters

Payload

The struct type whose fields are described.

Member Function Documentation

compare()

template<typename Payload >

virtual std::partial_ordering parcel::IPayloadFieldDescriptor< Payload >::compare ( Payload const &  a, Payload const &  b  ) const

pure virtual

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.

Implemented in parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >, and parcel::MemberFieldDescriptor< Payload, FieldT, CellT >.

from_json_into()

template<typename Payload >

virtual void parcel::IPayloadFieldDescriptor< Payload >::from_json_into ( json_t const &  field_json, Payload &  p, ParcelRegistry const &  reg  ) const

pure virtual

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.

Implemented in parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >, and parcel::MemberFieldDescriptor< Payload, FieldT, CellT >.

to_json_into()

template<typename Payload >

virtual void parcel::IPayloadFieldDescriptor< Payload >::to_json_into ( json_t &  v_obj, Payload const &  p  ) const

pure virtual

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.

Implemented in parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >, and parcel::MemberFieldDescriptor< Payload, FieldT, CellT >.

to_string_into()

template<typename Payload >

virtual void parcel::IPayloadFieldDescriptor< Payload >::to_string_into ( std::string &  out, Payload const &  p  ) const

pure virtual

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

Parameters

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

Implemented in parcel::InheritedFieldDescriptor< DerivedPayload, ParentPayload >, and parcel::MemberFieldDescriptor< Payload, FieldT, CellT >.

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

• include/parcel/struct.h