libweave: Port base/ changes from Chromium project
Now this makes the state of base/ match libchrome's implementation
on Brillo and Chrome OS.
Change-Id: I1c1eb30d2669aeb58a77f332f8c69f130d00878c
Reviewed-on: https://weave-review.googlesource.com/3065
Reviewed-by: Robert Ginda <rginda@google.com>
diff --git a/third_party/chromium/base/callback_internal.h b/third_party/chromium/base/callback_internal.h
index 6339437..3682bf9 100644
--- a/third_party/chromium/base/callback_internal.h
+++ b/third_party/chromium/base/callback_internal.h
@@ -15,13 +15,14 @@
#include <vector>
#include "base/base_export.h"
+#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
-#include "base/template_util.h"
namespace base {
namespace internal {
+template <CopyMode copy_mode>
class CallbackBase;
// BindStateBase is used to provide an opaque handle that the Callback
@@ -43,6 +44,7 @@
private:
friend class scoped_refptr<BindStateBase>;
+ template <CopyMode copy_mode>
friend class CallbackBase;
void AddRef();
@@ -58,10 +60,13 @@
// Holds the Callback methods that don't require specialization to reduce
// template bloat.
-class BASE_EXPORT CallbackBase {
+// CallbackBase<MoveOnly> is a direct base class of MoveOnly callbacks, and
+// CallbackBase<Copyable> uses CallbackBase<MoveOnly> for its implementation.
+template <>
+class BASE_EXPORT CallbackBase<CopyMode::MoveOnly> {
public:
- CallbackBase(const CallbackBase& c);
- CallbackBase& operator=(const CallbackBase& c);
+ CallbackBase(CallbackBase&& c);
+ CallbackBase& operator=(CallbackBase&& c);
// Returns true if Callback is null (doesn't refer to anything).
bool is_null() const { return bind_state_.get() == NULL; }
@@ -77,7 +82,7 @@
using InvokeFuncStorage = void(*)();
// Returns true if this callback equals |other|. |other| may be null.
- bool Equals(const CallbackBase& other) const;
+ bool EqualsInternal(const CallbackBase& other) const;
// Allow initializing of |bind_state_| via the constructor to avoid default
// initialization of the scoped_refptr. We do not also initialize
@@ -91,9 +96,27 @@
~CallbackBase();
scoped_refptr<BindStateBase> bind_state_;
- InvokeFuncStorage polymorphic_invoke_;
+ InvokeFuncStorage polymorphic_invoke_ = nullptr;
};
+// CallbackBase<Copyable> is a direct base class of Copyable Callbacks.
+template <>
+class BASE_EXPORT CallbackBase<CopyMode::Copyable>
+ : public CallbackBase<CopyMode::MoveOnly> {
+ public:
+ CallbackBase(const CallbackBase& c);
+ CallbackBase(CallbackBase&& c);
+ CallbackBase& operator=(const CallbackBase& c);
+ CallbackBase& operator=(CallbackBase&& c);
+ protected:
+ explicit CallbackBase(BindStateBase* bind_state)
+ : CallbackBase<CopyMode::MoveOnly>(bind_state) {}
+ ~CallbackBase() {}
+};
+
+extern template class CallbackBase<CopyMode::MoveOnly>;
+extern template class CallbackBase<CopyMode::Copyable>;
+
// A helper template to determine if given type is non-const move-only-type,
// i.e. if a value of the given type should be passed via std::move() in a
// destructive way. Types are considered to be move-only if they have a
@@ -103,7 +126,13 @@
// confuses template deduction in VS2013 with certain types such as
// std::unique_ptr.
// TODO(dcheng): Revisit this when Windows switches to VS2015 by default.
+
template <typename T> struct IsMoveOnlyType {
+ // Types YesType and NoType are guaranteed such that sizeof(YesType) <
+ // sizeof(NoType).
+ using YesType = char;
+ struct NoType { YesType dummy[2]; };
+
template <typename U>
static YesType Test(const typename U::MoveOnlyTypeForCPP03*);
@@ -116,8 +145,14 @@
// Specialization of IsMoveOnlyType so that std::unique_ptr is still considered
// move-only, even without the sentinel member.
-template <typename T>
-struct IsMoveOnlyType<std::unique_ptr<T>> : std::true_type {};
+template <typename T, typename D>
+struct IsMoveOnlyType<std::unique_ptr<T, D>> : std::true_type {};
+
+// Specialization of std::vector, so that it's considered move-only if the
+// element type is move-only. Allocator is explicitly ignored when determining
+// move-only status of the std::vector.
+template <typename T, typename Allocator>
+struct IsMoveOnlyType<std::vector<T, Allocator>> : IsMoveOnlyType<T> {};
template <typename>
struct CallbackParamTraitsForMoveOnlyType;
@@ -130,16 +165,7 @@
// http://connect.microsoft.com/VisualStudio/feedbackdetail/view/957801/compilation-error-with-variadic-templates
//
// This is a typetraits object that's used to take an argument type, and
-// extract a suitable type for storing and forwarding arguments.
-//
-// In particular, it strips off references, and converts arrays to
-// pointers for storage; and it avoids accidentally trying to create a
-// "reference of a reference" if the argument is a reference type.
-//
-// This array type becomes an issue for storage because we are passing bound
-// parameters by const reference. In this case, we end up passing an actual
-// array type in the initializer list which C++ does not allow. This will
-// break passing of C-string literals.
+// extract a suitable type for forwarding arguments.
template <typename T>
struct CallbackParamTraits
: std::conditional<IsMoveOnlyType<T>::value,
@@ -150,18 +176,6 @@
template <typename T>
struct CallbackParamTraitsForNonMoveOnlyType {
using ForwardType = const T&;
- using StorageType = T;
-};
-
-// The Storage should almost be impossible to trigger unless someone manually
-// specifies type of the bind parameters. However, in case they do,
-// this will guard against us accidentally storing a reference parameter.
-//
-// The ForwardType should only be used for unbound arguments.
-template <typename T>
-struct CallbackParamTraitsForNonMoveOnlyType<T&> {
- using ForwardType = T&;
- using StorageType = T;
};
// Note that for array types, we implicitly add a const in the conversion. This
@@ -172,14 +186,12 @@
template <typename T, size_t n>
struct CallbackParamTraitsForNonMoveOnlyType<T[n]> {
using ForwardType = const T*;
- using StorageType = const T*;
};
// See comment for CallbackParamTraits<T[n]>.
template <typename T>
struct CallbackParamTraitsForNonMoveOnlyType<T[]> {
using ForwardType = const T*;
- using StorageType = const T*;
};
// Parameter traits for movable-but-not-copyable scopers.
@@ -198,7 +210,6 @@
template <typename T>
struct CallbackParamTraitsForMoveOnlyType {
using ForwardType = T;
- using StorageType = T;
};
// CallbackForward() is a very limited simulation of C++11's std::forward()
