diff --git a/include/ircd/util/scope_count.h b/include/ircd/util/scope_count.h new file mode 100644 index 000000000..d81adb1ef --- /dev/null +++ b/include/ircd/util/scope_count.h @@ -0,0 +1,45 @@ +// Matrix Construct +// +// Copyright (C) Matrix Construct Developers, Authors & Contributors +// Copyright (C) 2016-2019 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. The +// full license for this software is available in the LICENSE file. + +#pragma once +#define HAVE_IRCD_UTIL_SCOPE_COUNT_H + +namespace ircd::util +{ + struct scope_count; +}; + +/// A simple boiler-plate for incrementing a counter when constructed and +/// decrementing it to its previous value when destructed. This takes a runtime +/// reference to that counter. +struct ircd::util::scope_count +{ + ulong *count {nullptr}; + + scope_count(ulong &count); + scope_count(const scope_count &) = delete; + scope_count(scope_count &&) noexcept = delete; + ~scope_count() noexcept; +}; + +inline +ircd::util::scope_count::scope_count(ulong &count) +:count{&count} +{ + ++count; +} + +inline +ircd::util::scope_count::~scope_count() +noexcept +{ + assert(count); + --(*count); +} diff --git a/include/ircd/util/util.h b/include/ircd/util/util.h index 57c134a00..4f7097711 100644 --- a/include/ircd/util/util.h +++ b/include/ircd/util/util.h @@ -46,6 +46,7 @@ namespace ircd #include "tuple.h" #include "timer.h" #include "scope_light.h" +#include "scope_count.h" #include "life_guard.h" #include "pubsetbuf.h" #include "string.h"