From ac30a4709ff225c8c93337ee61709b33d3772d76 Mon Sep 17 00:00:00 2001
From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Wed, 8 Nov 2023 15:57:04 -0500
Subject: [PATCH] cpp-common/bt2: remove useless copy operations

This patch removes useless copy constructors and assignment operators
from many wrapper classes in `cpp-common/bt2` where the compiler
generates some anyway.

Also, return by value (like everywhere else) from pseudo copy
operations.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Change-Id: I9e5b5e956905681c3a834122b3f0ed8311b5a6ae
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11302
Reviewed-by: Simon Marchi <simon.marchi@efficios.com>
---
 src/cpp-common/bt2/borrowed-object.hpp   |  6 +---
 src/cpp-common/bt2/clock-class.hpp       |  3 --
 src/cpp-common/bt2/clock-snapshot.hpp    | 11 -------
 src/cpp-common/bt2/field-class.hpp       | 42 ++++++++++++------------
 src/cpp-common/bt2/field-path.hpp        | 31 -----------------
 src/cpp-common/bt2/field.hpp             | 36 +++++++++-----------
 src/cpp-common/bt2/integer-range-set.hpp |  2 +-
 src/cpp-common/bt2/integer-range.hpp     | 10 ------
 src/cpp-common/bt2/message.hpp           | 18 +++++-----
 src/cpp-common/bt2/trace-ir.hpp          | 14 ++++----
 src/cpp-common/bt2/value.hpp             | 16 ++++-----
 11 files changed, 62 insertions(+), 127 deletions(-)

diff --git a/src/cpp-common/bt2/borrowed-object.hpp b/src/cpp-common/bt2/borrowed-object.hpp
index 6b1f6e57..678fed82 100644
--- a/src/cpp-common/bt2/borrowed-object.hpp
+++ b/src/cpp-common/bt2/borrowed-object.hpp
@@ -87,10 +87,6 @@ protected:
         BT_ASSERT_DBG(libObjPtr);
     }
 
-    /* Default copy operations */
-    BorrowedObject(const BorrowedObject&) noexcept = default;
-    BorrowedObject& operator=(const BorrowedObject&) noexcept = default;
-
     /*
      * Generic "copy" constructor.
      *
@@ -126,7 +122,7 @@ protected:
      * context in the compiler error message.
      */
     template <typename OtherLibObjT>
-    _ThisBorrowedObject& operator=(const BorrowedObject<OtherLibObjT>& other) noexcept
+    _ThisBorrowedObject operator=(const BorrowedObject<OtherLibObjT>& other) noexcept
     {
         static_assert(_AssignableFromConst<OtherLibObjT>::val,
                       "Don't assign a non-const wrapper from a const wrapper.");
diff --git a/src/cpp-common/bt2/clock-class.hpp b/src/cpp-common/bt2/clock-class.hpp
index 35ddfbfa..bd127dfa 100644
--- a/src/cpp-common/bt2/clock-class.hpp
+++ b/src/cpp-common/bt2/clock-class.hpp
@@ -72,9 +72,6 @@ public:
     {
     }
 
-    ClockClassOffset(const ClockClassOffset&) noexcept = default;
-    ClockClassOffset& operator=(const ClockClassOffset&) noexcept = default;
-
     std::int64_t seconds() const noexcept
     {
         return _mSeconds;
diff --git a/src/cpp-common/bt2/clock-snapshot.hpp b/src/cpp-common/bt2/clock-snapshot.hpp
index ed30eaf5..190eb6a2 100644
--- a/src/cpp-common/bt2/clock-snapshot.hpp
+++ b/src/cpp-common/bt2/clock-snapshot.hpp
@@ -24,17 +24,6 @@ public:
     {
     }
 
-    ConstClockSnapshot(const ConstClockSnapshot& clkSnapshot) noexcept :
-        _ThisBorrowedObject {clkSnapshot}
-    {
-    }
-
-    ConstClockSnapshot& operator=(const ConstClockSnapshot& clkSnapshot) noexcept
-    {
-        _ThisBorrowedObject::operator=(clkSnapshot);
-        return *this;
-    }
-
     std::uint64_t value() const noexcept
     {
         return bt_clock_snapshot_get_value(this->libObjPtr());
diff --git a/src/cpp-common/bt2/field-class.hpp b/src/cpp-common/bt2/field-class.hpp
index 95d3f8b2..13ac7b4f 100644
--- a/src/cpp-common/bt2/field-class.hpp
+++ b/src/cpp-common/bt2/field-class.hpp
@@ -184,7 +184,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonFieldClass& operator=(const CommonFieldClass<OtherLibObjT> fc) noexcept
+    CommonFieldClass operator=(const CommonFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisBorrowedObject::operator=(fc);
         return *this;
@@ -472,7 +472,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBitArrayFieldClass<LibObjT>&
+    CommonBitArrayFieldClass<LibObjT>
     operator=(const CommonBitArrayFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
@@ -552,7 +552,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonIntegerFieldClass& operator=(const CommonIntegerFieldClass<OtherLibObjT> fc) noexcept
+    CommonIntegerFieldClass operator=(const CommonIntegerFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
         return *this;
@@ -686,7 +686,7 @@ public:
     {
     }
 
-    ConstEnumerationFieldClassMapping&
+    ConstEnumerationFieldClassMapping
     operator=(const ConstEnumerationFieldClassMapping& mapping) noexcept
     {
         _ThisBorrowedObject::operator=(mapping);
@@ -793,7 +793,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBaseEnumerationFieldClass&
+    CommonBaseEnumerationFieldClass
     operator=(const CommonBaseEnumerationFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonIntegerFieldClass::operator=(fc);
@@ -842,7 +842,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonEnumerationFieldClass&
+    CommonEnumerationFieldClass
     operator=(const CommonEnumerationFieldClass<OtherLibObjT, MappingT> fc) noexcept
     {
         CommonEnumerationFieldClass::operator=(fc);
@@ -1013,7 +1013,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStructureFieldClassMember<LibObjT>&
+    CommonStructureFieldClassMember<LibObjT>
     operator=(const CommonStructureFieldClassMember<OtherLibObjT> fc) noexcept
     {
         _ThisBorrowedObject::operator=(fc);
@@ -1143,7 +1143,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStructureFieldClass& operator=(const CommonStructureFieldClass<OtherLibObjT> fc) noexcept
+    CommonStructureFieldClass operator=(const CommonStructureFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
         return *this;
@@ -1289,7 +1289,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonArrayFieldClass& operator=(const CommonArrayFieldClass<OtherLibObjT> fc) noexcept
+    CommonArrayFieldClass operator=(const CommonArrayFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
         return *this;
@@ -1358,7 +1358,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStaticArrayFieldClass&
+    CommonStaticArrayFieldClass
     operator=(const CommonStaticArrayFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonArrayFieldClass::operator=(fc);
@@ -1428,7 +1428,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonDynamicArrayWithLengthFieldClass&
+    CommonDynamicArrayWithLengthFieldClass
     operator=(const CommonDynamicArrayWithLengthFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonArrayFieldClass::operator=(fc);
@@ -1530,7 +1530,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonOptionFieldClass& operator=(const CommonOptionFieldClass<OtherLibObjT> fc) noexcept
+    CommonOptionFieldClass operator=(const CommonOptionFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
         return *this;
@@ -1603,7 +1603,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonOptionWithSelectorFieldClass&
+    CommonOptionWithSelectorFieldClass
     operator=(const CommonOptionWithSelectorFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonOptionFieldClass::operator=(fc);
@@ -1677,7 +1677,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonOptionWithBoolSelectorFieldClass&
+    CommonOptionWithBoolSelectorFieldClass
     operator=(const CommonOptionWithBoolSelectorFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonOptionWithSelectorFieldClass::operator=(fc);
@@ -1782,7 +1782,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonOptionWithIntegerSelectorFieldClass&
+    CommonOptionWithIntegerSelectorFieldClass
     operator=(const CommonOptionWithIntegerSelectorFieldClass<OtherLibObjT, RangeSetT> fc) noexcept
     {
         _ThisCommonOptionWithSelectorFieldClass::operator=(fc);
@@ -1911,7 +1911,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantFieldClassOption&
+    CommonVariantFieldClassOption
     operator=(const CommonVariantFieldClassOption<OtherLibObjT> fc) noexcept
     {
         _ThisBorrowedObject::operator=(fc);
@@ -2058,7 +2058,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    ConstVariantWithIntegerSelectorFieldClassOption&
+    ConstVariantWithIntegerSelectorFieldClassOption
     operator=(const ConstVariantWithIntegerSelectorFieldClassOption<OtherLibObjT> fc) noexcept
     {
         _ThisBorrowedObject::operator=(fc);
@@ -2165,7 +2165,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantFieldClass& operator=(const CommonVariantFieldClass<OtherLibObjT> fc) noexcept
+    CommonVariantFieldClass operator=(const CommonVariantFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonFieldClass::operator=(fc);
         return *this;
@@ -2267,7 +2267,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantWithoutSelectorFieldClass&
+    CommonVariantWithoutSelectorFieldClass
     operator=(const CommonVariantWithoutSelectorFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonVariantFieldClass::operator=(fc);
@@ -2420,7 +2420,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantWithSelectorFieldClass&
+    CommonVariantWithSelectorFieldClass
     operator=(const CommonVariantWithSelectorFieldClass<OtherLibObjT> fc) noexcept
     {
         _ThisCommonVariantFieldClass::operator=(fc);
@@ -2481,7 +2481,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantWithIntegerSelectorFieldClass&
+    CommonVariantWithIntegerSelectorFieldClass
     operator=(const CommonVariantWithIntegerSelectorFieldClass<OtherLibObjT, OptionT> fc) noexcept
     {
         _ThisCommonVariantWithSelectorFieldClass::operator=(fc);
diff --git a/src/cpp-common/bt2/field-path.hpp b/src/cpp-common/bt2/field-path.hpp
index 69f48455..300b7376 100644
--- a/src/cpp-common/bt2/field-path.hpp
+++ b/src/cpp-common/bt2/field-path.hpp
@@ -36,16 +36,6 @@ public:
     {
     }
 
-    ConstFieldPathItem(const ConstFieldPathItem& fpItem) noexcept : _ThisBorrowedObject {fpItem}
-    {
-    }
-
-    ConstFieldPathItem& operator=(const ConstFieldPathItem& fpItem) noexcept
-    {
-        _ThisBorrowedObject::operator=(fpItem);
-        return *this;
-    }
-
     FieldPathItemType type() const noexcept
     {
         return static_cast<FieldPathItemType>(this->_libType());
@@ -84,17 +74,6 @@ public:
         BT_ASSERT_DBG(this->isIndex());
     }
 
-    ConstIndexFieldPathItem(const ConstIndexFieldPathItem& fpItem) noexcept :
-        ConstFieldPathItem {fpItem}
-    {
-    }
-
-    ConstIndexFieldPathItem& operator=(const ConstIndexFieldPathItem& fpItem) noexcept
-    {
-        ConstFieldPathItem::operator=(fpItem);
-        return *this;
-    }
-
     std::uint64_t index() const noexcept
     {
         return bt_field_path_item_index_get_index(this->libObjPtr());
@@ -142,16 +121,6 @@ public:
     {
     }
 
-    ConstFieldPath(const ConstFieldPath& fieldPath) noexcept : _ThisBorrowedObject {fieldPath}
-    {
-    }
-
-    ConstFieldPath& operator=(const ConstFieldPath& fieldPath) noexcept
-    {
-        _ThisBorrowedObject::operator=(fieldPath);
-        return *this;
-    }
-
     Scope rootScope() const noexcept
     {
         return static_cast<Scope>(bt_field_path_get_root_scope(this->libObjPtr()));
diff --git a/src/cpp-common/bt2/field.hpp b/src/cpp-common/bt2/field.hpp
index b69295b2..cb9359e7 100644
--- a/src/cpp-common/bt2/field.hpp
+++ b/src/cpp-common/bt2/field.hpp
@@ -115,7 +115,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonField& operator=(const CommonField<OtherLibObjT> val) noexcept
+    _ThisCommonField operator=(const CommonField<OtherLibObjT> val) noexcept
     {
         _ThisBorrowedObject::operator=(val);
         return *this;
@@ -272,7 +272,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBoolField<LibObjT>& operator=(const CommonBoolField<OtherLibObjT> val) noexcept
+    CommonBoolField<LibObjT> operator=(const CommonBoolField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -346,7 +346,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBitArrayField<LibObjT>& operator=(const CommonBitArrayField<OtherLibObjT> val) noexcept
+    CommonBitArrayField<LibObjT> operator=(const CommonBitArrayField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -438,7 +438,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonUnsignedIntegerField&
+    _ThisCommonUnsignedIntegerField
     operator=(const CommonUnsignedIntegerField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
@@ -524,7 +524,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonSignedIntegerField&
+    _ThisCommonSignedIntegerField
     operator=(const CommonSignedIntegerField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
@@ -593,12 +593,6 @@ public:
     {
     }
 
-    EnumerationFieldClassMappingLabels(const EnumerationFieldClassMappingLabels&) noexcept =
-        default;
-
-    EnumerationFieldClassMappingLabels&
-    operator=(const EnumerationFieldClassMappingLabels&) noexcept = default;
-
     std::uint64_t length() const noexcept
     {
         return _mLen;
@@ -639,7 +633,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonUnsignedEnumerationField<LibObjT>&
+    CommonUnsignedEnumerationField<LibObjT>
     operator=(const CommonUnsignedEnumerationField<OtherLibObjT> val) noexcept
     {
         _ThisCommonUnsignedIntegerField::operator=(val);
@@ -718,7 +712,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonSignedEnumerationField<LibObjT>&
+    CommonSignedEnumerationField<LibObjT>
     operator=(const CommonSignedEnumerationField<OtherLibObjT> val) noexcept
     {
         _ThisCommonSignedIntegerField::operator=(val);
@@ -797,7 +791,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonSinglePrecisionRealField<LibObjT>&
+    CommonSinglePrecisionRealField<LibObjT>
     operator=(const CommonSinglePrecisionRealField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
@@ -875,7 +869,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonDoublePrecisionRealField<LibObjT>&
+    CommonDoublePrecisionRealField<LibObjT>
     operator=(const CommonDoublePrecisionRealField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
@@ -950,7 +944,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStringField<LibObjT>& operator=(const CommonStringField<OtherLibObjT> val) noexcept
+    CommonStringField<LibObjT> operator=(const CommonStringField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -1097,7 +1091,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStructureField<LibObjT>& operator=(const CommonStructureField<OtherLibObjT> val) noexcept
+    CommonStructureField<LibObjT> operator=(const CommonStructureField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -1213,7 +1207,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonArrayField& operator=(const CommonArrayField<OtherLibObjT> val) noexcept
+    _ThisCommonArrayField operator=(const CommonArrayField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -1284,7 +1278,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonDynamicArrayField<LibObjT>&
+    CommonDynamicArrayField<LibObjT>
     operator=(const CommonDynamicArrayField<OtherLibObjT> val) noexcept
     {
         _ThisCommonArrayField::operator=(val);
@@ -1382,7 +1376,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonOptionField<LibObjT>& operator=(const CommonOptionField<OtherLibObjT> val) noexcept
+    CommonOptionField<LibObjT> operator=(const CommonOptionField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
@@ -1491,7 +1485,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonVariantField<LibObjT>& operator=(const CommonVariantField<OtherLibObjT> val) noexcept
+    CommonVariantField<LibObjT> operator=(const CommonVariantField<OtherLibObjT> val) noexcept
     {
         _ThisCommonField::operator=(val);
         return *this;
diff --git a/src/cpp-common/bt2/integer-range-set.hpp b/src/cpp-common/bt2/integer-range-set.hpp
index 07de9431..1cfbfc3a 100644
--- a/src/cpp-common/bt2/integer-range-set.hpp
+++ b/src/cpp-common/bt2/integer-range-set.hpp
@@ -171,7 +171,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonIntegerRangeSet& operator=(const CommonIntegerRangeSet<OtherLibObjT> rangeSet) noexcept
+    CommonIntegerRangeSet operator=(const CommonIntegerRangeSet<OtherLibObjT> rangeSet) noexcept
     {
         _ThisBorrowedObject::operator=(rangeSet);
         return *this;
diff --git a/src/cpp-common/bt2/integer-range.hpp b/src/cpp-common/bt2/integer-range.hpp
index aafc22e5..026e1d52 100644
--- a/src/cpp-common/bt2/integer-range.hpp
+++ b/src/cpp-common/bt2/integer-range.hpp
@@ -82,16 +82,6 @@ public:
     {
     }
 
-    ConstIntegerRange(const ConstIntegerRange& range) noexcept : _ThisBorrowedObject {range}
-    {
-    }
-
-    ConstIntegerRange& operator=(const ConstIntegerRange& range) noexcept
-    {
-        _ThisBorrowedObject::operator=(range);
-        return *this;
-    }
-
     bool operator==(const ConstIntegerRange& other) const noexcept
     {
         return internal::ConstIntegerRangeSpec<LibObjT>::isEqual(this->libObjPtr(),
diff --git a/src/cpp-common/bt2/message.hpp b/src/cpp-common/bt2/message.hpp
index 1de0c481..ff0240d2 100644
--- a/src/cpp-common/bt2/message.hpp
+++ b/src/cpp-common/bt2/message.hpp
@@ -101,7 +101,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonMessage& operator=(const CommonMessage<OtherLibObjT> val) noexcept
+    _ThisCommonMessage operator=(const CommonMessage<OtherLibObjT> val) noexcept
     {
         _ThisBorrowedObject::operator=(val);
         return *this;
@@ -248,7 +248,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStreamBeginningMessage<LibObjT>&
+    CommonStreamBeginningMessage<LibObjT>
     operator=(const CommonStreamBeginningMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -363,7 +363,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStreamEndMessage<LibObjT>&
+    CommonStreamEndMessage<LibObjT>
     operator=(const CommonStreamEndMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -477,7 +477,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonPacketBeginningMessage<LibObjT>&
+    CommonPacketBeginningMessage<LibObjT>
     operator=(const CommonPacketBeginningMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -587,7 +587,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonPacketEndMessage<LibObjT>&
+    CommonPacketEndMessage<LibObjT>
     operator=(const CommonPacketEndMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -696,7 +696,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonEventMessage<LibObjT>& operator=(const CommonEventMessage<OtherLibObjT> val) noexcept
+    CommonEventMessage<LibObjT> operator=(const CommonEventMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
         return *this;
@@ -796,7 +796,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonDiscardedEventsMessage<LibObjT>&
+    CommonDiscardedEventsMessage<LibObjT>
     operator=(const CommonDiscardedEventsMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -927,7 +927,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonDiscardedPacketsMessage<LibObjT>&
+    CommonDiscardedPacketsMessage<LibObjT>
     operator=(const CommonDiscardedPacketsMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
@@ -1035,7 +1035,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonMessageIteratorInactivityMessage<LibObjT>&
+    CommonMessageIteratorInactivityMessage<LibObjT>
     operator=(const CommonMessageIteratorInactivityMessage<OtherLibObjT> val) noexcept
     {
         _ThisCommonMessage::operator=(val);
diff --git a/src/cpp-common/bt2/trace-ir.hpp b/src/cpp-common/bt2/trace-ir.hpp
index b5557d7d..14863e18 100644
--- a/src/cpp-common/bt2/trace-ir.hpp
+++ b/src/cpp-common/bt2/trace-ir.hpp
@@ -151,7 +151,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonEvent<LibObjT>& operator=(const CommonEvent<OtherLibObjT> event) noexcept
+    CommonEvent<LibObjT> operator=(const CommonEvent<OtherLibObjT> event) noexcept
     {
         _ThisBorrowedObject::operator=(event);
         return *this;
@@ -292,7 +292,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonPacket& operator=(const CommonPacket<OtherLibObjT> packet) noexcept
+    CommonPacket operator=(const CommonPacket<OtherLibObjT> packet) noexcept
     {
         _ThisBorrowedObject::operator=(packet);
         return *this;
@@ -444,7 +444,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStream& operator=(const CommonStream<OtherLibObjT> stream) noexcept
+    CommonStream operator=(const CommonStream<OtherLibObjT> stream) noexcept
     {
         _ThisBorrowedObject::operator=(stream);
         return *this;
@@ -658,7 +658,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonTrace& operator=(const CommonTrace<OtherLibObjT> trace) noexcept
+    CommonTrace operator=(const CommonTrace<OtherLibObjT> trace) noexcept
     {
         _ThisBorrowedObject::operator=(trace);
         return *this;
@@ -977,7 +977,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonEventClass& operator=(const CommonEventClass<OtherLibObjT> eventClass) noexcept
+    CommonEventClass operator=(const CommonEventClass<OtherLibObjT> eventClass) noexcept
     {
         _ThisBorrowedObject::operator=(eventClass);
         return *this;
@@ -1302,7 +1302,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStreamClass& operator=(const CommonStreamClass<OtherLibObjT> streamClass) noexcept
+    CommonStreamClass operator=(const CommonStreamClass<OtherLibObjT> streamClass) noexcept
     {
         _ThisBorrowedObject::operator=(streamClass);
         return *this;
@@ -1731,7 +1731,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonTraceClass& operator=(const CommonTraceClass<OtherLibObjT> traceClass) noexcept
+    CommonTraceClass operator=(const CommonTraceClass<OtherLibObjT> traceClass) noexcept
     {
         _ThisBorrowedObject::operator=(traceClass);
         return *this;
diff --git a/src/cpp-common/bt2/value.hpp b/src/cpp-common/bt2/value.hpp
index fe5a434d..cfbc92b5 100644
--- a/src/cpp-common/bt2/value.hpp
+++ b/src/cpp-common/bt2/value.hpp
@@ -129,7 +129,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonValue& operator=(const CommonValue<OtherLibObjT> val) noexcept
+    _ThisCommonValue operator=(const CommonValue<OtherLibObjT> val) noexcept
     {
         _ThisBorrowedObject::operator=(val);
         return *this;
@@ -410,7 +410,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonNullValue<LibObjT>& operator=(const CommonNullValue<OtherLibObjT> val) noexcept
+    CommonNullValue<LibObjT> operator=(const CommonNullValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -480,7 +480,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBoolValue<LibObjT>& operator=(const CommonBoolValue<OtherLibObjT> val) noexcept
+    CommonBoolValue<LibObjT> operator=(const CommonBoolValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -569,7 +569,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonUnsignedIntegerValue<LibObjT>&
+    CommonUnsignedIntegerValue<LibObjT>
     operator=(const CommonUnsignedIntegerValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
@@ -749,7 +749,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonRealValue<LibObjT>& operator=(const CommonRealValue<OtherLibObjT> val) noexcept
+    CommonRealValue<LibObjT> operator=(const CommonRealValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -841,7 +841,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonStringValue<LibObjT>& operator=(const CommonStringValue<OtherLibObjT> val) noexcept
+    CommonStringValue<LibObjT> operator=(const CommonStringValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -962,7 +962,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonArrayValue<LibObjT>& operator=(const CommonArrayValue<OtherLibObjT> val) noexcept
+    CommonArrayValue<LibObjT> operator=(const CommonArrayValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -1265,7 +1265,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonMapValue<LibObjT>& operator=(const CommonMapValue<OtherLibObjT> val) noexcept
+    CommonMapValue<LibObjT> operator=(const CommonMapValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
-- 
2.34.1