real::compat::detail::lazy_std_engine< StdRegex > Class Template Reference

An engine built on first use and published once: a reader after the build takes no lock, and a copy made while another thread builds sees the finished engine or none (and then builds its own). Copyable, so the regex that holds it stays copyable. More...

#include <regex_core.hpp>

Public Member Functions
	lazy_std_engine (const lazy_std_engine &other)
	Copies other's engine if it is published.
	lazy_std_engine (lazy_std_engine &&other) noexcept
	Takes other's engine if it is published; other is left without one.
lazy_std_engine &	operator= (const lazy_std_engine &other)
	Replaces this engine with a copy of other's, if published.
lazy_std_engine &	operator= (lazy_std_engine &&other) noexcept
	Replaces this engine with other's, if published; other is left without one.
const StdRegex *	get () const noexcept
	The published engine.
const StdRegex &	publish (StdRegex &&engine) const
	Publishes engine; the caller holds the build lock and has seen get return null.
void	reset () noexcept
	Drops the engine; not concurrent with any other use of this object.
void	swap (lazy_std_engine &other) noexcept
	Exchanges the engines; not concurrent with any other use of either object.

Private Member Functions
void	copy_from (const lazy_std_engine &other)
	Copies other's engine if published; this one holds none.

Private Attributes
std::optional< StdRegex >	value_
	The engine, set once under the build lock.
std::atomic< bool >	ready_ {false}
	Released after value_ is set: acquire it before reading.

Detailed Description

template<typename StdRegex>
class real::compat::detail::lazy_std_engine< StdRegex >

An engine built on first use and published once: a reader after the build takes no lock, and a copy made while another thread builds sees the finished engine or none (and then builds its own). Copyable, so the regex that holds it stays copyable.

Template Parameters

StdRegex

The engine: a std::basic_regex, or the end_variants of a REAL pattern.

Constructor & Destructor Documentation

lazy_std_engine() [1/2]

template<typename StdRegex >

real::compat::detail::lazy_std_engine< StdRegex >::lazy_std_engine ( const lazy_std_engine< StdRegex > &  other )

inline

Copies other's engine if it is published.

Parameters

[in]

other

The source.

lazy_std_engine() [2/2]

template<typename StdRegex >

real::compat::detail::lazy_std_engine< StdRegex >::lazy_std_engine ( lazy_std_engine< StdRegex > &&  other )

inlinenoexcept

Takes other's engine if it is published; other is left without one.

Parameters

[in,out]

other

The source.

Member Function Documentation

copy_from()

template<typename StdRegex >

void real::compat::detail::lazy_std_engine< StdRegex >::copy_from ( const lazy_std_engine< StdRegex > &  other )

inlineprivate

Copies other's engine if published; this one holds none.

Parameters

[in]

other

The source.

get()

template<typename StdRegex >

const StdRegex * real::compat::detail::lazy_std_engine< StdRegex >::get ( ) const

inlinenoexcept

The published engine.

Returns

It, or null before publish.

operator=() [1/2]

template<typename StdRegex >

lazy_std_engine & real::compat::detail::lazy_std_engine< StdRegex >::operator= ( const lazy_std_engine< StdRegex > &  other )

inline

Replaces this engine with a copy of other's, if published.

Parameters

[in]

other

The source.

Returns

This.

operator=() [2/2]

template<typename StdRegex >

lazy_std_engine & real::compat::detail::lazy_std_engine< StdRegex >::operator= ( lazy_std_engine< StdRegex > &&  other )

inlinenoexcept

Replaces this engine with other's, if published; other is left without one.

Parameters

[in,out]

other

The source.

Returns

This.

publish()

template<typename StdRegex >

const StdRegex & real::compat::detail::lazy_std_engine< StdRegex >::publish ( StdRegex &&  engine ) const

inline

Publishes engine; the caller holds the build lock and has seen get return null.

Parameters

[in]

engine

The built engine.

Returns

The published engine.

swap()

template<typename StdRegex >

void real::compat::detail::lazy_std_engine< StdRegex >::swap ( lazy_std_engine< StdRegex > &  other )

inlinenoexcept

Exchanges the engines; not concurrent with any other use of either object.

Parameters

[in,out]

other

The other engine.

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

• include/real/compat/std/regex_core.hpp