MayaFlux::Kakshya::Composite Class Reference

Read view of one value in a CompositeArray. More...

#include <Composite.hpp>

Collaboration diagram for MayaFlux::Kakshya::Composite:

Public Member Functions
std::optional< std::span< const uint8_t > >	blob (std::string_view field_name) const noexcept
	Borrow the bytes of a fixed or dynamic BLOB field.
template<typename T > requires ArithmeticData<T>
std::optional< T >	get (std::string_view field_name) const noexcept
	Read a present arithmetic field by exact value type.
bool	has (std::string_view field_name) const noexcept
	Whether a named field exists and is present in this element.
const CompositeLayout &	layout () const noexcept
	Layout used to interpret this element's packed bytes.
std::optional< std::string_view >	text (std::string_view field_name) const noexcept
	Read a present std::string field as borrowed UTF-8 bytes.
std::optional< CompositeValue >	value (std::string_view field_name) const noexcept
	Borrow a dynamic value; an absent field returns std::nullopt.

Private Member Functions
	Composite (const CompositeLayout &layout, const DataVariant &rows, const DataVariant &text, const DataVariant &blob, size_t index) noexcept

Private Attributes
const DataVariant *	m_blob
size_t	m_index
const CompositeLayout *	m_layout
const DataVariant *	m_rows
const DataVariant *	m_text

Friends
class	CompositeAccess
class	CompositeArray
class	CompositeInsertion

Detailed Description

Read view of one value in a CompositeArray.

Borrows a layout and three DataVariant stores. Arithmetic access copies one value from packed bytes, so the field need not be naturally aligned. Numeric getters require an exact declared type, except dynamic INTEGER and REAL fields which accept int64_t and double respectively. Missing and mismatched fields return std::nullopt.

Usage:

auto item = items.at(0);
auto name = item->text("name");
auto score = item->get<double>("score");
bool has_age = item->has("age");

Note

The backing layout and DataVariant objects must outlive this view. Text and byte views may be invalidated by later writes to their stores.

Definition at line 130 of file Composite.hpp.

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

• Composite.hpp
• Composite.cpp