Add MoveTo to pcommon.Value, only type missing this (open-telemetry#12877)

Signed-off-by: Bogdan Drutu <[email protected]>

Author: bogdandrutu

.chloggen/value_move.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pdata
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add MoveTo to pcommon.Value, only type missing this
+
+# One or more tracking issues or pull requests related to the change
+issues: [12877]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pdata/pcommon/value.go

@@ -318,6 +318,16 @@ func (v Value) SetEmptySlice() Slice {
 	return newSlice(&av.ArrayValue.Values, v.getState())
 }
 
+// MoveTo moves the Value from current overriding the destination and
+// resetting the current instance to empty value.
+// Calling this function on zero-initialized Value will cause a panic.
+func (v Value) MoveTo(dest Value) {
+	v.getState().AssertMutable()
+	dest.getState().AssertMutable()
+	*dest.getOrig() = *v.getOrig()
+	v.getOrig().Value = nil
+}
+
 // CopyTo copies the Value instance overriding the destination.
 // Calling this function on zero-initialized Value will cause a panic.
 func (v Value) CopyTo(dest Value) {

pdata/pcommon/value_test.go

@@ -231,6 +231,21 @@ func TestNilOrigSetValue(t *testing.T) {
 	assert.Equal(t, []any{int64(1), "val"}, av.Slice().AsRaw())
 }
 
+func TestValue_MoveTo(t *testing.T) {
+	src := NewValueMap()
+	src.Map().PutStr("key", "value")
+
+	dest := NewValueEmpty()
+	assert.True(t, dest.Equal(NewValueEmpty()))
+
+	src.MoveTo(dest)
+	assert.True(t, src.Equal(NewValueEmpty()))
+
+	expected := NewValueMap()
+	expected.Map().PutStr("key", "value")
+	assert.True(t, dest.Equal(expected))
+}
+
 func TestValue_CopyTo(t *testing.T) {
 	state := internal.StateMutable