Delegate.h File Reference

Implementation details for multi-signature Delegate. More...

Detailed Description

Implementation details for multi-signature Delegate.

This file contains the internal implementation mechanisms for the Delegate class. It provides:

• Linear class hierarchy (LCH) for combining multiple callback signatures
• Type-erased callback storage using function pointers
• SFINAE-based compile-time signature matching
• Invoker utilities for dispatching to the correct handler method

These are internal implementation details and should not be used directly. Use the Delegate class from Delegate.h instead.

Note

This is an implementation header - do not include directly

See also

Delegate

#include <type_traits>
#include <core/src/Utils.h>

Classes
struct	b2bits::delegate_detail::LCH< T, Args >
	Linear class hierarchy node (recursive case). More...
struct	b2bits::delegate_detail::LCH< T >
	Linear class hierarchy node (base case). More...
struct	b2bits::delegate_detail::ArgsPack< T, Args >
	Type list wrapper for function arguments. More...
struct	b2bits::delegate_detail::CallbackPtr< R, Args >
	Type-erased callback storage. More...
struct	b2bits::delegate_detail::MakePtr< R(Args...)>
	Specialization of MakePtr for function types. More...
struct	b2bits::delegate_detail::Callbacks< Args >
	Metafunction to create callbacks hierarchy from signatures. More...
struct	b2bits::delegate_detail::Invoker
	Invoker utility for dispatching calls to handler objects. More...
struct	b2bits::delegate_detail::ForEach< Callbacks >
	Recursively assign handler to all callbacks in hierarchy. More...
struct	b2bits::delegate_detail::ForEach< void >
	ForEach specialization for base case (void parent). More...
struct	b2bits::delegate_detail::Delete
	Sentinel type for handler destruction. More...

Namespaces
namespace	b2bits
namespace	b2bits::delegate_detail

Functions
template<class Callbacks, class Decl>
constexpr bool	b2bits::delegate_detail::is_invocable ()
	Check if callbacks hierarchy supports a specific signature (compile-time).
template<class Decl, class Callbacks>
std::enable_if< is_invocable< Callbacks, Decl >(), bool >::type	b2bits::delegate_detail::is_assigned (const Callbacks &cbs)
	Check if a callback is assigned for a specific signature (runtime).
template<class Decl, class Callbacks>
std::enable_if< is_invocable< Callbacks, Decl >(), void >::type	b2bits::delegate_detail::clear (Callbacks &cbs)
	Clear (nullify) a callback for a specific signature.

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Class Documentation

b2bits::delegate_detail::ArgsPack

struct b2bits::delegate_detail::ArgsPack

template<typename T, typename... Args>
struct b2bits::delegate_detail::ArgsPack< T, Args >

Type list wrapper for function arguments.

Wraps a list of argument types for passing to template metaprogramming utilities. Used to carry function signature information through the type system.

Template Parameters

T	First argument type
Args	Remaining argument types

b2bits::delegate_detail::MakePtr< R(Args...)>

struct b2bits::delegate_detail::MakePtr< R(Args...)>

template<class R, class... Args>
struct b2bits::delegate_detail::MakePtr< R(Args...)>

Specialization of MakePtr for function types.

Extracts return type and arguments from function signature and creates a CallbackPtr with void* prepended to arguments.

Template Parameters

R	Return type
Args	Argument types

Class Members
typedef CallbackPtr< R, void *, Args... >	type CallbackPtr<R, void*, Args...>	CallbackPtr with void* prepended.

b2bits::delegate_detail::Callbacks

struct b2bits::delegate_detail::Callbacks

template<class... Args>
struct b2bits::delegate_detail::Callbacks< Args >

Metafunction to create callbacks hierarchy from signatures.

Takes multiple function signatures and creates a linear class hierarchy (LCH) of CallbackPtr types, one for each signature.

Template Parameters

Args	Function signatures (e.g., void(int), void(string))

Class Members
typedef type... >	type LCH<typename MakePtr<Args>::type...>	LCH of all callbacks.

b2bits::delegate_detail::Delete

struct b2bits::delegate_detail::Delete

Sentinel type for handler destruction.

Special empty type used as a signature for the destructor callback. The delegate uses void(Delete) as a signature to store a function that destroys the handler object.