| // Copyright 2012 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_APPLE_SCOPED_NSOBJECT_H_ |
| #define BASE_APPLE_SCOPED_NSOBJECT_H_ |
| |
| // Include NSObject.h directly because Foundation.h pulls in many dependencies. |
| // (Approx 100k lines of code versus 1.5k for NSObject.h). scoped_nsobject gets |
| // singled out because it is most typically included from other header files. |
| #import <Foundation/NSObject.h> |
| |
| #include <type_traits> |
| |
| #include "base/apple/scoped_typeref.h" |
| #include "base/base_export.h" |
| #include "base/compiler_specific.h" |
| |
| #if HAS_FEATURE(objc_arc) |
| #error "Do not use scoped_nsobject in ARC code; use __strong instead." |
| #endif |
| |
| @class NSAutoreleasePool; |
| |
| namespace base::apple { |
| |
| // scoped_nsobject<> is patterned after std::unique_ptr<>, but maintains |
| // ownership of an NSObject subclass object. Style deviations here are solely |
| // for compatibility with std::unique_ptr<>'s interface, with which everyone is |
| // already familiar. |
| // |
| // scoped_nsobject<> takes ownership of an object (in the constructor or in |
| // reset()) by taking over the caller's existing ownership claim. The caller |
| // must own the object it gives to scoped_nsobject<>, and relinquishes an |
| // ownership claim to that object. scoped_nsobject<> does not call -retain, |
| // callers have to call this manually if appropriate. |
| // |
| // scoped_nsprotocol<> has the same behavior as scoped_nsobject, but can be used |
| // with protocols. |
| // |
| // scoped_nsobject<> is not to be used for NSAutoreleasePools. For C++ code use |
| // NSAutoreleasePool; for Objective-C(++) code use @autoreleasepool instead. We |
| // check for bad uses of scoped_nsobject and NSAutoreleasePool at compile time |
| // with a template specialization (see below). |
| |
| namespace internal { |
| |
| template <typename NST> |
| struct ScopedNSProtocolTraits { |
| static NST InvalidValue() { return nil; } |
| static NST Retain(NST nst) { return [nst retain]; } |
| static void Release(NST nst) { [nst release]; } |
| }; |
| |
| } // namespace internal |
| |
| template <typename NST> |
| class scoped_nsprotocol |
| : public ScopedTypeRef<NST, internal::ScopedNSProtocolTraits<NST>> { |
| public: |
| using ScopedTypeRef<NST, |
| internal::ScopedNSProtocolTraits<NST>>::ScopedTypeRef; |
| |
| // Shift reference to the autorelease pool to be released later. |
| NST autorelease() { return [this->release() autorelease]; } |
| }; |
| |
| // Free functions |
| template <class C> |
| void swap(scoped_nsprotocol<C>& p1, scoped_nsprotocol<C>& p2) { |
| p1.swap(p2); |
| } |
| |
| template <class C> |
| bool operator==(C p1, const scoped_nsprotocol<C>& p2) { |
| return p1 == p2.get(); |
| } |
| |
| template <class C> |
| bool operator!=(C p1, const scoped_nsprotocol<C>& p2) { |
| return p1 != p2.get(); |
| } |
| |
| template <typename NST> |
| class scoped_nsobject : public scoped_nsprotocol<NST*> { |
| public: |
| using scoped_nsprotocol<NST*>::scoped_nsprotocol; |
| |
| static_assert(std::is_same_v<NST, NSAutoreleasePool> == false, |
| "Use @autoreleasepool instead"); |
| }; |
| |
| // Specialization to make scoped_nsobject<id> work. |
| template <> |
| class scoped_nsobject<id> : public scoped_nsprotocol<id> { |
| public: |
| using scoped_nsprotocol<id>::scoped_nsprotocol; |
| }; |
| |
| } // namespace base::apple |
| |
| #endif // BASE_APPLE_SCOPED_NSOBJECT_H_ |