mirror of
https://github.com/mollyim/webrtc.git
synced 2025-05-15 06:40:43 +01:00
00579e8bce
This extends AlwaysValidPointer to take a lambda for its default rather than requesting a constructor. Bug: none Change-Id: Ied97968c3f511af15422a1eef9801d14d4ec5b96 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/260580 Reviewed-by: Jonas Oreland <jonaso@webrtc.org> Commit-Queue: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#36745}
110 lines
4 KiB
C++
110 lines
4 KiB
C++
/*
|
|
* Copyright 2022 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
#ifndef RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
|
|
#define RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
|
|
|
|
#include <memory>
|
|
#include <utility>
|
|
|
|
#include "rtc_base/checks.h"
|
|
|
|
namespace webrtc {
|
|
|
|
// This template allows the instantiation of a pointer to Interface in such a
|
|
// way that if it is passed a null pointer, an object of class Default will be
|
|
// created, which will be deallocated when the pointer is deleted.
|
|
template <typename Interface, typename Default = Interface>
|
|
class AlwaysValidPointer {
|
|
public:
|
|
explicit AlwaysValidPointer(Interface* pointer)
|
|
: owned_instance_(pointer ? nullptr : std::make_unique<Default>()),
|
|
pointer_(pointer ? pointer : owned_instance_.get()) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
template <typename Arg,
|
|
typename std::enable_if<!(std::is_invocable<Arg>::value),
|
|
bool>::type = true>
|
|
AlwaysValidPointer(Interface* pointer, Arg arg)
|
|
: owned_instance_(pointer ? nullptr
|
|
: std::make_unique<Default>(std::move(arg))),
|
|
pointer_(pointer ? pointer : owned_instance_.get()) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
// Multiple arguments
|
|
template <typename Arg1, typename... Args>
|
|
AlwaysValidPointer(Interface* pointer, Arg1 arg1, Args... args)
|
|
: owned_instance_(pointer
|
|
? nullptr
|
|
: std::make_unique<Default>(std::move(arg1),
|
|
std::move(args...))),
|
|
pointer_(pointer ? pointer : owned_instance_.get()) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
// Create a pointer by
|
|
// a) using |pointer|, without taking ownership
|
|
// b) calling |function| and taking ownership of the result
|
|
template <typename Func,
|
|
typename std::enable_if<std::is_invocable<Func>::value,
|
|
bool>::type = true>
|
|
AlwaysValidPointer(Interface* pointer, Func function)
|
|
: owned_instance_(pointer ? nullptr : function()),
|
|
pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
// Create a pointer by
|
|
// a) taking over ownership of |instance|
|
|
// b) or fallback to |pointer|, without taking ownership.
|
|
// c) or Default.
|
|
AlwaysValidPointer(std::unique_ptr<Interface>&& instance, Interface* pointer)
|
|
: owned_instance_(
|
|
instance
|
|
? std::move(instance)
|
|
: (pointer == nullptr ? std::make_unique<Default>() : nullptr)),
|
|
pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
// Create a pointer by
|
|
// a) taking over ownership of |instance|
|
|
// b) or fallback to |pointer|, without taking ownership.
|
|
// c) or Default (with forwarded args).
|
|
template <typename... Args>
|
|
AlwaysValidPointer(std::unique_ptr<Interface>&& instance,
|
|
Interface* pointer,
|
|
Args... args)
|
|
: owned_instance_(
|
|
instance ? std::move(instance)
|
|
: (pointer == nullptr
|
|
? std::make_unique<Default>(std::move(args...))
|
|
: nullptr)),
|
|
pointer_(owned_instance_ ? owned_instance_.get() : pointer) {
|
|
RTC_DCHECK(pointer_);
|
|
}
|
|
|
|
Interface* get() { return pointer_; }
|
|
Interface* operator->() { return pointer_; }
|
|
Interface& operator*() { return *pointer_; }
|
|
|
|
Interface* get() const { return pointer_; }
|
|
Interface* operator->() const { return pointer_; }
|
|
Interface& operator*() const { return *pointer_; }
|
|
|
|
private:
|
|
const std::unique_ptr<Interface> owned_instance_;
|
|
Interface* const pointer_;
|
|
};
|
|
|
|
} // namespace webrtc
|
|
|
|
#endif // RTC_BASE_MEMORY_ALWAYS_VALID_POINTER_H_
|