microfmt::log::log_sink Class Reference

Type-erased, two-word handle to a log sink backend, plus the severity threshold below which records are dropped before ever reaching the backend. More...

#include <sink.hpp>

Classes
struct	vtable
	Virtual table of log sink operations. More...

Public Member Functions
constexpr	log_sink () noexcept=default
	Constructs an empty (invalid) handle.
template<typename Tag , typename Traits = log_sink_traits<Tag>, std::enable_if_t< std::is_void_v< typename Traits::context_type >, int > = 0>
constexpr	log_sink (Tag, level lvl=level::trace) noexcept
	Constructs a handle for a stateless log sink tag.
template<typename Tag , typename Context , typename Traits = log_sink_traits<Tag>, std::enable_if_t<!std::is_void_v< typename Traits::context_type > &&std::is_convertible_v< Context *, typename Traits::context_type * >, int > = 0>
constexpr	log_sink (Tag, Context &ctx RELOCO_LIFETIMEBOUND RELOCO_LIFETIME_CAPTURE_BY_THIS, level lvl=level::trace) noexcept
	Constructs a handle for a stateful log sink tag.
template<typename Tag , typename Context , std::enable_if_t<!std::is_lvalue_reference_v< Context >, int > = 0>
constexpr	log_sink (Tag, Context &&, level=level::trace)=delete
void	log (const log_msg &msg) noexcept
	Emits msg to the underlying backend, honoring both the record's own level check and this sink's configured threshold.
constexpr bool	can_flush () const noexcept
	Reports whether the bound backend supports flush.
void	flush () noexcept
	Flushes buffered output. A no-op when can_flush is false.
void	set_level (level l) noexcept
constexpr bool	should_log (level l) const noexcept
constexpr	operator bool () const noexcept
	Reports whether the handle is bound to a log sink backend.

Detailed Description

Type-erased, two-word handle to a log sink backend, plus the severity threshold below which records are dropped before ever reaching the backend.

Packs a context pointer and a vtable pointer into two words: no virtual base class, no RTTI, and no allocation of its own. The bound context (for stateful tags) must outlive every log_sink built from it.

Constructor & Destructor Documentation

log_sink() [1/4]

constexpr microfmt::log::log_sink::log_sink ( )

constexprdefaultnoexcept

Constructs an empty (invalid) handle.

log_sink() [2/4]

template<typename Tag , typename Traits = log_sink_traits<Tag>, std::enable_if_t< std::is_void_v< typename Traits::context_type >, int > = 0>

constexpr microfmt::log::log_sink::log_sink ( Tag  , level  lvl = level::trace  )

inlineexplicitconstexprnoexcept

Constructs a handle for a stateless log sink tag.

Template Parameters

Tag	Log sink tag type.
Traits	Specialized traits, enabled when context_type is void.

Parameters

lvl	Severity threshold below which records are dropped.

log_sink() [3/4]

template<typename Tag , typename Context , typename Traits = log_sink_traits<Tag>, std::enable_if_t<!std::is_void_v< typename Traits::context_type > &&std::is_convertible_v< Context *, typename Traits::context_type * >, int > = 0>

constexpr microfmt::log::log_sink::log_sink ( Tag  , Context &ctx RELOCO_LIFETIMEBOUND  RELOCO_LIFETIME_CAPTURE_BY_THIS, level  lvl = level::trace  )

inlineconstexprnoexcept

Constructs a handle for a stateful log sink tag.

Template Parameters

Tag	Log sink tag type.
Context	Concrete context type.
Traits	Specialized traits, enabled when context_type is non-void and Context converts to it.

Parameters

ctx	Context object backing the writes.
lvl	Severity threshold below which records are dropped.

log_sink() [4/4]

template<typename Tag , typename Context , std::enable_if_t<!std::is_lvalue_reference_v< Context >, int > = 0>

constexpr microfmt::log::log_sink::log_sink ( Tag  , Context &&  , level  = level::trace  )

constexprdelete

Member Function Documentation

can_flush()

constexpr bool microfmt::log::log_sink::can_flush ( ) const

inlineconstexprnoexcept

Reports whether the bound backend supports flush.

flush()

void microfmt::log::log_sink::flush ( )

inlinenoexcept

Flushes buffered output. A no-op when can_flush is false.

log()

void microfmt::log::log_sink::log ( const log_msg &  msg )

inlinenoexcept

Emits msg to the underlying backend, honoring both the record's own level check and this sink's configured threshold.

operator bool()

constexpr microfmt::log::log_sink::operator bool ( ) const

inlineexplicitconstexprnoexcept

Reports whether the handle is bound to a log sink backend.

set_level()

void microfmt::log::log_sink::set_level ( level  l )

inlinenoexcept

should_log()

constexpr bool microfmt::log::log_sink::should_log ( level  l ) const

inlineconstexprnoexcept

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

• include/microfmt/log/sink.hpp