From bda4351c365466e57af5e6ea76e24c76c160e834 Mon Sep 17 00:00:00 2001
From: Axel Naumann <Axel.Naumann@cern.ch>
Date: Mon, 9 Oct 2017 12:07:37 +0200
Subject: [PATCH] Make TUniWeak out-streamable without weak_ptr or variant
support.
Create two members, weak and unique_ptr, as I/O cannot handle variant. So we stream both.
O, and I/O cannot handle weak_ptr, but we really need it, so at least support writing (through THttpServer) by adding a `T*` with the same
value as the weak ptr, and have that streamed. This completely breaks the internal symmetry of TUniWeak, but it should get us started...
---
core/base/v7/inc/ROOT/TDrawable.hxx | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/core/base/v7/inc/ROOT/TDrawable.hxx b/core/base/v7/inc/ROOT/TDrawable.hxx
index 392a2b217be..7f2e22fa588 100644
--- a/core/base/v7/inc/ROOT/TDrawable.hxx
+++ b/core/base/v7/inc/ROOT/TDrawable.hxx
@@ -52,11 +52,12 @@ namespace Internal {
template <class T>
class TUniWeakPtr {
- union {
+ // Needs I/O support for union (or variant, actually) {
std::unique_ptr<T> fUnique;
- std::weak_ptr<T> fWeak;
- };
- bool fIsWeak; ///< fUnique or fWeak?
+ std::weak_ptr<T> fWeak; //! Cannot save for now :-(
+ T* fWeakForIO = nullptr; // Hack to allow streaming *out* of fWeak (reading is still broken because we don't set fWeak)
+ // };
+ bool fIsWeak = false; ///< fUnique or fWeak?
public:
/// \class Accessor
@@ -97,22 +98,22 @@ public:
}
};
- TUniWeakPtr(const std::shared_ptr<T> &ptr): fWeak(ptr), fIsWeak(true) {}
+ TUniWeakPtr() = default;
+ TUniWeakPtr(const std::shared_ptr<T> &ptr): fWeak(ptr), fWeakForIO(ptr.get()), fIsWeak(true) {}
TUniWeakPtr(std::unique_ptr<T> &&ptr): fUnique(std::move(ptr)), fIsWeak(false) {}
TUniWeakPtr(TUniWeakPtr &&rhs): fIsWeak(rhs.fIsWeak)
{
- if (fIsWeak) {
- fWeak.weak_ptr(std::move(rhs.fWeak));
- } else
- fWeak.unique_ptr(std::move(rhs.fUnique));
+ if (rhs.fIsWeak) {
+ fWeak = std::move(rhs.fWeak);
+ auto shptr = rhs.fWeak.lock();
+ fWeakForIO = shptr.get();
+ } else {
+ fUnique = std::move(rhs.fUnique);
+ }
}
~TUniWeakPtr()
{
- if (fIsWeak)
- fWeak.~weak_ptr();
- else
- fUnique.~unique_ptr();
}
Accessor Get() const { return Accessor(*this); }
--
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