mirror of
https://github.com/matrix-construct/construct
synced 2024-11-09 11:31:11 +01:00
77 lines
2.5 KiB
C++
77 lines
2.5 KiB
C++
// Copyright (C) Matrix Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2018 Jason Volk
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
// DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
|
|
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
|
// IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
// POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
#pragma once
|
|
#define HAVE_IRCD_UTIL_INSTANCE_LIST_H
|
|
|
|
namespace ircd::util
|
|
{
|
|
template<class T> struct instance_list;
|
|
}
|
|
|
|
/// The instance_list pattern is where every instance of a class registers
|
|
/// itself in a static list of all instances and removes itself on dtor.
|
|
/// IRCd Ex. All clients use instance_list so all clients can be listed for
|
|
/// an administrator or be interrupted and disconnected on server shutdown.
|
|
///
|
|
/// `struct myobj : ircd::instance_list<myobj> {};`
|
|
///
|
|
/// * The creator of the class no longer has to manually specify what is
|
|
/// defined here using unique_iterator; however, one still must provide
|
|
/// linkage for the static list.
|
|
///
|
|
/// * The container pointer used by unique_iterator is eliminated here
|
|
/// because of the static list.
|
|
///
|
|
template<class T>
|
|
struct ircd::util::instance_list
|
|
{
|
|
static std::list<T *> list;
|
|
|
|
protected:
|
|
typename decltype(list)::iterator it;
|
|
|
|
instance_list(typename decltype(list)::iterator it)
|
|
:it{std::move(it)}
|
|
{}
|
|
|
|
instance_list()
|
|
:it{list.emplace(end(list), static_cast<T *>(this))}
|
|
{}
|
|
|
|
instance_list(const instance_list &) = delete;
|
|
instance_list(instance_list &&o) noexcept
|
|
:it{std::move(o.it)}
|
|
{
|
|
o.it = end(list);
|
|
}
|
|
|
|
instance_list &operator=(const instance_list &) = delete;
|
|
instance_list &operator=(instance_list &&o) noexcept
|
|
{
|
|
std::swap(it, o.it);
|
|
return *this;
|
|
}
|
|
|
|
~instance_list() noexcept
|
|
{
|
|
if(it != end(list))
|
|
list.erase(it);
|
|
}
|
|
};
|