cpp-common/bt2: pass wrappers by value instead of by reference

[babeltrace.git] / src / cpp-common / bt2 / value.hpp

diff --git a/src/cpp-common/bt2/value.hpp b/src/cpp-common/bt2/value.hpp
index dd05fea53fcc4404fb4c961c63518d2d263205fd..6e05cd0d36c80625f8a35a30c7f187bb850f697b 100644 (file)
--- a/src/cpp-common/bt2/value.hpp
+++ b/src/cpp-common/bt2/value.hpp
@@ -21,10 +21,9 @@
 #include "internal/utils.hpp"
 #include "cpp-common/optional.hpp"
 #include "cpp-common/string_view.hpp"
-#include "lib-error.hpp"
+#include "exc.hpp"
 
 namespace bt2 {
-
 namespace internal {
 
 struct ValueRefFuncs final
@@ -135,12 +134,12 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonValue(const CommonValue<OtherLibObjT>& val) noexcept : _ThisBorrowedObj {val}
+    CommonValue(const CommonValue<OtherLibObjT> val) noexcept : _ThisBorrowedObj {val}
     {
     }
 
     template <typename OtherLibObjT>
-    _ThisCommonValue& operator=(const CommonValue<OtherLibObjT>& val) noexcept
+    _ThisCommonValue& operator=(const CommonValue<OtherLibObjT> val) noexcept
     {
         _ThisBorrowedObj::operator=(val);
         return *this;
@@ -197,20 +196,26 @@ public:
     }
 
     template <typename OtherLibObjT>
-    bool operator==(const CommonValue<OtherLibObjT>& other) const noexcept
+    bool operator==(const CommonValue<OtherLibObjT> other) const noexcept
     {
         return static_cast<bool>(bt_value_is_equal(this->libObjPtr(), other.libObjPtr()));
     }
 
     template <typename OtherLibObjT>
-    bool operator!=(const CommonValue<OtherLibObjT>& other) const noexcept
+    bool operator!=(const CommonValue<OtherLibObjT> other) const noexcept
     {
         return !(*this == other);
     }
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
+    }
+
+    template <typename ValueT>
+    ValueT as() const noexcept
+    {
+        return ValueT {this->libObjPtr()};
     }
 
     CommonNullValue<LibObjT> asNull() const noexcept;
@@ -232,6 +237,26 @@ protected:
 using Value = CommonValue<bt_value>;
 using ConstValue = CommonValue<const bt_value>;
 
+namespace internal {
+
+struct ValueTypeDescr
+{
+    using Const = ConstValue;
+    using NonConst = Value;
+};
+
+template <>
+struct TypeDescr<Value> : public ValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstValue> : public ValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonNullValue final : public CommonValue<LibObjT>
 {
@@ -246,12 +271,12 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonNullValue(const CommonNullValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonNullValue(const CommonNullValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
-    CommonNullValue<LibObjT>& operator=(const CommonNullValue<OtherLibObjT>& val) noexcept
+    CommonNullValue<LibObjT>& operator=(const CommonNullValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -259,13 +284,33 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
 using NullValue = CommonNullValue<bt_value>;
 using ConstNullValue = CommonNullValue<const bt_value>;
 
+namespace internal {
+
+struct NullValueTypeDescr
+{
+    using Const = ConstNullValue;
+    using NonConst = NullValue;
+};
+
+template <>
+struct TypeDescr<NullValue> : public NullValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstNullValue> : public NullValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonBoolValue final : public CommonValue<LibObjT>
 {
@@ -283,7 +328,7 @@ public:
     }
 
     template <typename OtherLibObjT>
-    CommonBoolValue(const CommonBoolValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonBoolValue(const CommonBoolValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
@@ -292,11 +337,11 @@ public:
         const auto libObjPtr = bt_value_bool_create_init(static_cast<bt_bool>(rawVal));
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonBoolValue<LibObjT> {libObjPtr}};
+        return CommonBoolValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonBoolValue<LibObjT>& operator=(const CommonBoolValue<OtherLibObjT>& val) noexcept
+    CommonBoolValue<LibObjT>& operator=(const CommonBoolValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -322,13 +367,33 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
 using BoolValue = CommonBoolValue<bt_value>;
 using ConstBoolValue = CommonBoolValue<const bt_value>;
 
+namespace internal {
+
+struct BoolValueTypeDescr
+{
+    using Const = ConstBoolValue;
+    using NonConst = BoolValue;
+};
+
+template <>
+struct TypeDescr<BoolValue> : public BoolValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstBoolValue> : public BoolValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonUnsignedIntegerValue final : public CommonValue<LibObjT>
 {
@@ -351,18 +416,18 @@ public:
         const auto libObjPtr = bt_value_integer_unsigned_create_init(rawVal);
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonUnsignedIntegerValue<LibObjT> {libObjPtr}};
+        return CommonUnsignedIntegerValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonUnsignedIntegerValue(const CommonUnsignedIntegerValue<OtherLibObjT>& val) noexcept :
+    CommonUnsignedIntegerValue(const CommonUnsignedIntegerValue<OtherLibObjT> val) noexcept :
         _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
     CommonUnsignedIntegerValue<LibObjT>&
-    operator=(const CommonUnsignedIntegerValue<OtherLibObjT>& val) noexcept
+    operator=(const CommonUnsignedIntegerValue<OtherLibObjT> val) noexcept
     {
         static_assert(!std::is_const<LibObjT>::value, "`LibObjT` must NOT be `const`.");
 
@@ -388,13 +453,33 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
 using UnsignedIntegerValue = CommonUnsignedIntegerValue<bt_value>;
 using ConstUnsignedIntegerValue = CommonUnsignedIntegerValue<const bt_value>;
 
+namespace internal {
+
+struct UnsignedIntegerValueTypeDescr
+{
+    using Const = ConstUnsignedIntegerValue;
+    using NonConst = UnsignedIntegerValue;
+};
+
+template <>
+struct TypeDescr<UnsignedIntegerValue> : public UnsignedIntegerValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstUnsignedIntegerValue> : public UnsignedIntegerValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonSignedIntegerValue final : public CommonValue<LibObjT>
 {
@@ -417,18 +502,18 @@ public:
         const auto libObjPtr = bt_value_integer_signed_create_init(rawVal);
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonSignedIntegerValue<LibObjT> {libObjPtr}};
+        return CommonSignedIntegerValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonSignedIntegerValue(const CommonSignedIntegerValue<OtherLibObjT>& val) noexcept :
+    CommonSignedIntegerValue(const CommonSignedIntegerValue<OtherLibObjT> val) noexcept :
         _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
     CommonSignedIntegerValue<LibObjT>&
-    operator=(const CommonSignedIntegerValue<OtherLibObjT>& val) noexcept
+    operator=(const CommonSignedIntegerValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -454,13 +539,33 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
 using SignedIntegerValue = CommonSignedIntegerValue<bt_value>;
 using ConstSignedIntegerValue = CommonSignedIntegerValue<const bt_value>;
 
+namespace internal {
+
+struct SignedIntegerValueTypeDescr
+{
+    using Const = ConstSignedIntegerValue;
+    using NonConst = SignedIntegerValue;
+};
+
+template <>
+struct TypeDescr<SignedIntegerValue> : public SignedIntegerValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstSignedIntegerValue> : public SignedIntegerValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonRealValue final : public CommonValue<LibObjT>
 {
@@ -482,16 +587,16 @@ public:
         const auto libObjPtr = bt_value_real_create_init(rawVal);
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonRealValue<LibObjT> {libObjPtr}};
+        return CommonRealValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonRealValue(const CommonRealValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonRealValue(const CommonRealValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
-    CommonRealValue<LibObjT>& operator=(const CommonRealValue<OtherLibObjT>& val) noexcept
+    CommonRealValue<LibObjT>& operator=(const CommonRealValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -517,13 +622,33 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
 using RealValue = CommonRealValue<bt_value>;
 using ConstRealValue = CommonRealValue<const bt_value>;
 
+namespace internal {
+
+struct RealValueTypeDescr
+{
+    using Const = ConstRealValue;
+    using NonConst = RealValue;
+};
+
+template <>
+struct TypeDescr<RealValue> : public RealValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstRealValue> : public RealValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 class CommonStringValue final : public CommonValue<LibObjT>
 {
@@ -544,21 +669,21 @@ public:
         const auto libObjPtr = bt_value_string_create_init(rawVal);
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonStringValue<LibObjT> {libObjPtr}};
+        return CommonStringValue::Shared::createWithoutRef(libObjPtr);
     }
 
     static Shared create(const std::string& rawVal)
     {
-        return CommonStringValue<LibObjT>::create(rawVal.data());
+        return CommonStringValue::create(rawVal.data());
     }
 
     template <typename OtherLibObjT>
-    CommonStringValue(const CommonStringValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonStringValue(const CommonStringValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
-    CommonStringValue<LibObjT>& operator=(const CommonStringValue<OtherLibObjT>& val) noexcept
+    CommonStringValue<LibObjT>& operator=(const CommonStringValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -571,7 +696,7 @@ public:
         const auto status = bt_value_string_set(this->libObjPtr(), rawVal);
 
         if (status == BT_VALUE_STRING_SET_STATUS_MEMORY_ERROR) {
-            throw LibMemoryError {};
+            throw MemoryError {};
         }
 
         return *this;
@@ -589,7 +714,7 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 };
 
@@ -598,6 +723,22 @@ using ConstStringValue = CommonStringValue<const bt_value>;
 
 namespace internal {
 
+struct StringValueTypeDescr
+{
+    using Const = ConstStringValue;
+    using NonConst = StringValue;
+};
+
+template <>
+struct TypeDescr<StringValue> : public StringValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstStringValue> : public StringValueTypeDescr
+{
+};
+
 template <typename LibObjT>
 struct CommonArrayValueSpec;
 
@@ -645,16 +786,16 @@ public:
         const auto libObjPtr = bt_value_array_create();
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonArrayValue<LibObjT> {libObjPtr}};
+        return CommonArrayValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonArrayValue(const CommonArrayValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonArrayValue(const CommonArrayValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
-    CommonArrayValue<LibObjT>& operator=(const CommonArrayValue<OtherLibObjT>& val) noexcept
+    CommonArrayValue<LibObjT>& operator=(const CommonArrayValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -698,7 +839,7 @@ public:
             internal::CommonArrayValueSpec<LibObjT>::elementByIndex(this->libObjPtr(), index)};
     }
 
-    void append(const Value& val)
+    void append(const Value val)
     {
         static_assert(!std::is_const<LibObjT>::value, "`LibObjT` must NOT be `const`.");
 
@@ -762,7 +903,7 @@ public:
     CommonArrayValue<bt_value> appendEmptyArray();
     CommonMapValue<bt_value> appendEmptyMap();
 
-    void operator+=(const Value& val)
+    void operator+=(const Value val)
     {
         this->append(val);
     }
@@ -799,14 +940,14 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 
 private:
     void _handleAppendLibStatus(const bt_value_array_append_element_status status) const
     {
         if (status == BT_VALUE_ARRAY_APPEND_ELEMENT_STATUS_MEMORY_ERROR) {
-            throw LibMemoryError {};
+            throw MemoryError {};
         }
     }
 };
@@ -816,6 +957,22 @@ using ConstArrayValue = CommonArrayValue<const bt_value>;
 
 namespace internal {
 
+struct ArrayValueTypeDescr
+{
+    using Const = ConstArrayValue;
+    using NonConst = ArrayValue;
+};
+
+template <>
+struct TypeDescr<ArrayValue> : public ArrayValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstArrayValue> : public ArrayValueTypeDescr
+{
+};
+
 /*
  * Type of a user function passed to `CommonMapValue<ObjT>::forEach()`.
  *
@@ -877,7 +1034,7 @@ struct CommonMapValueSpec<bt_value> final
             return;
         case BT_VALUE_MAP_FOREACH_ENTRY_STATUS_USER_ERROR:
         case BT_VALUE_MAP_FOREACH_ENTRY_STATUS_ERROR:
-            throw LibError {};
+            throw Error {};
         default:
             bt_common_abort();
         }
@@ -910,7 +1067,7 @@ struct CommonMapValueSpec<const bt_value> final
             return;
         case BT_VALUE_MAP_FOREACH_ENTRY_CONST_STATUS_USER_ERROR:
         case BT_VALUE_MAP_FOREACH_ENTRY_CONST_STATUS_ERROR:
-            throw LibError {};
+            throw Error {};
         default:
             bt_common_abort();
         }
@@ -939,16 +1096,16 @@ public:
         const auto libObjPtr = bt_value_map_create();
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return Shared {CommonMapValue<LibObjT> {libObjPtr}};
+        return CommonMapValue::Shared::createWithoutRef(libObjPtr);
     }
 
     template <typename OtherLibObjT>
-    CommonMapValue(const CommonMapValue<OtherLibObjT>& val) noexcept : _ThisCommonValue {val}
+    CommonMapValue(const CommonMapValue<OtherLibObjT> val) noexcept : _ThisCommonValue {val}
     {
     }
 
     template <typename OtherLibObjT>
-    CommonMapValue<LibObjT>& operator=(const CommonMapValue<OtherLibObjT>& val) noexcept
+    CommonMapValue<LibObjT>& operator=(const CommonMapValue<OtherLibObjT> val) noexcept
     {
         _ThisCommonValue::operator=(val);
         return *this;
@@ -1008,7 +1165,7 @@ public:
         return this->hasEntry(key.data());
     }
 
-    void insert(const char * const key, const Value& val)
+    void insert(const char * const key, const Value val)
     {
         static_assert(!std::is_const<LibObjT>::value, "`LibObjT` must NOT be `const`.");
 
@@ -1017,7 +1174,7 @@ public:
         this->_handleInsertLibStatus(status);
     }
 
-    void insert(const std::string& key, const Value& val)
+    void insert(const std::string& key, const Value val)
     {
         this->insert(key.data(), val);
     }
@@ -1122,14 +1279,14 @@ public:
 
     Shared shared() const noexcept
     {
-        return Shared {*this};
+        return Shared::createWithRef(*this);
     }
 
 private:
     void _handleInsertLibStatus(const bt_value_map_insert_entry_status status) const
     {
         if (status == BT_VALUE_MAP_INSERT_ENTRY_STATUS_MEMORY_ERROR) {
-            throw LibMemoryError {};
+            throw MemoryError {};
         }
     }
 };
@@ -1137,6 +1294,26 @@ private:
 using MapValue = CommonMapValue<bt_value>;
 using ConstMapValue = CommonMapValue<const bt_value>;
 
+namespace internal {
+
+struct MapValueTypeDescr
+{
+    using Const = ConstMapValue;
+    using NonConst = MapValue;
+};
+
+template <>
+struct TypeDescr<MapValue> : public MapValueTypeDescr
+{
+};
+
+template <>
+struct TypeDescr<ConstMapValue> : public MapValueTypeDescr
+{
+};
+
+} /* namespace internal */
+
 template <typename LibObjT>
 CommonNullValue<LibObjT> CommonValue<LibObjT>::asNull() const noexcept
 {