Lazy, functional-style query/filter view over a snapshot of registered threads. More...

#include <thread_registry_backend.hpp>

Public Member Functions
	query_view (std::vector< registered_thread_info_backend > entries)

template<typename Predicate >
auto	filter (Predicate &&pred) const -> query_view

template<typename Fn >
void	for_each (Fn &&fn) const

auto	count () const -> size_t

auto	empty () const -> bool

auto	entries () const -> std::vector< registered_thread_info_backend > const &

template<typename Fn >
auto	map (Fn &&fn) const -> std::vector< std::invoke_result_t< Fn, registered_thread_info_backend const & > >

template<typename Predicate >
auto	find_if (Predicate &&pred) const -> std::optional< registered_thread_info_backend >

template<typename Predicate >
auto	any (Predicate &&pred) const -> bool

template<typename Predicate >
auto	all (Predicate &&pred) const -> bool

template<typename Predicate >
auto	none (Predicate &&pred) const -> bool

auto	take (size_t n) const -> query_view

auto	skip (size_t n) const -> query_view

Detailed Description

Lazy, functional-style query/filter view over a snapshot of registered threads.

A query_view is produced by thread_registry_backend::query() (or by chaining operations on an existing query_view). It holds an internal std::vector<registered_thread_info_backend> that is a snapshot - mutations to the originating thread_registry_backend after the query_view was created are not visible.

Value semantics: query_view is a regular value type (copyable and movable). All transformation methods (filter, take, skip) return a new query_view, leaving the original unchanged.

Thread safety: A single query_view instance is not safe to use concurrently from multiple threads. However, it is safe to create multiple QueryViews concurrently from the same thread_registry_backend, since creation acquires a shared lock on the registry.

API

Provides a functional-style interface:

filter(pred) - returns a new query_view containing only entries that satisfy pred.
map(fn) - transforms each entry and returns a std::vector<R>.
for_each(fn) - applies fn to every entry.
find_if(pred) - returns the first matching entry, or std::nullopt.
any / all / none(pred) - boolean aggregation predicates.
take(n) / skip(n) - positional slicing, returning new QueryViews.
count() / empty() - size queries.
entries() - direct access to the underlying vector.

Definition at line 220 of file thread_registry_backend.hpp.

Constructor & Destructor Documentation

◆ query_view()

threadschedule::detail::thread_registry_backend::query_view::query_view ( std::vector< registered_thread_info_backend > entries )

inlineexplicit

Definition at line 223 of file thread_registry_backend.hpp.

Member Function Documentation

◆ all()

template<typename Predicate >

auto threadschedule::detail::thread_registry_backend::query_view::all ( Predicate && pred ) const -> bool

inline

Definition at line 308 of file thread_registry_backend.hpp.

References map().

◆ any()

template<typename Predicate >

auto threadschedule::detail::thread_registry_backend::query_view::any ( Predicate && pred ) const -> bool

inline

Definition at line 296 of file thread_registry_backend.hpp.

References map().

Referenced by none().

◆ count()

auto threadschedule::detail::thread_registry_backend::query_view::count ( ) const -> size_t

inline

Definition at line 250 of file thread_registry_backend.hpp.

◆ empty()

auto threadschedule::detail::thread_registry_backend::query_view::empty ( ) const -> bool

inline

Definition at line 256 of file thread_registry_backend.hpp.

◆ entries()

auto threadschedule::detail::thread_registry_backend::query_view::entries ( ) const -> std::vector<registered_thread_info_backend> const&

inline

Definition at line 262 of file thread_registry_backend.hpp.

◆ filter()

template<typename Predicate >

auto threadschedule::detail::thread_registry_backend::query_view::filter ( Predicate && pred ) const -> query_view

inline

Definition at line 227 of file thread_registry_backend.hpp.

References map().

◆ find_if()

template<typename Predicate >

auto threadschedule::detail::thread_registry_backend::query_view::find_if ( Predicate && pred ) const -> std::optional<registered_thread_info_backend>

inline

Definition at line 284 of file thread_registry_backend.hpp.

References map().

◆ for_each()

template<typename Fn >

void threadschedule::detail::thread_registry_backend::query_view::for_each ( Fn && fn ) const

inline

Definition at line 241 of file thread_registry_backend.hpp.

References map().

◆ map()

template<typename Fn >

auto threadschedule::detail::thread_registry_backend::query_view::map ( Fn && fn ) const -> std::vector<std::invoke_result_t<Fn, registered_thread_info_backend const&>>

inline

Definition at line 270 of file thread_registry_backend.hpp.

References map().

Referenced by all(), any(), filter(), find_if(), for_each(), map(), none(), skip(), and take().