Merge pull request #1355 from goplus/feature/reflect-indirect

feat(reflect): add Indirect function

_demo/go/reflectindirect/reflect-indirect.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"reflect"
+)
+
+func main() {
+	x := 42
+	p := &x
+
+	// Test 1: Non-pointer value - should return same value
+	v1 := reflect.Indirect(reflect.ValueOf(x))
+	if !v1.IsValid() || v1.Interface() != 42 {
+		panic("Non-pointer test failed: expected 42")
+	}
+
+	// Test 2: Pointer - should dereference
+	v2 := reflect.Indirect(reflect.ValueOf(p))
+	if !v2.IsValid() || v2.Interface() != 42 {
+		panic("Pointer dereference test failed: expected 42")
+	}
+
+	// Test 3: Nil pointer - should return invalid Value
+	var nilPtr *int
+	v3 := reflect.Indirect(reflect.ValueOf(nilPtr))
+	if v3.IsValid() {
+		panic("Nil pointer test failed: expected invalid Value")
+	}
+
+	// Test 4: Struct value - should return same value
+	type Person struct {
+		Name string
+		Age  int
+	}
+	person := Person{Name: "Alice", Age: 30}
+	v4 := reflect.Indirect(reflect.ValueOf(person))
+	if !v4.IsValid() || v4.Interface().(Person).Name != "Alice" || v4.Interface().(Person).Age != 30 {
+		panic("Struct value test failed: expected Person{Name: Alice, Age: 30}")
+	}
+
+	// Test 5: Struct pointer - should dereference
+	personPtr := &Person{Name: "Bob", Age: 25}
+	v5 := reflect.Indirect(reflect.ValueOf(personPtr))
+	if !v5.IsValid() || v5.Interface().(Person).Name != "Bob" || v5.Interface().(Person).Age != 25 {
+		panic("Struct pointer test failed: expected Person{Name: Bob, Age: 25}")
+	}
+
+	println("PASS")
+}

runtime/internal/lib/reflect/value.go

@@ -1759,6 +1759,16 @@ func ValueOf(i any) Value {
 	return unpackEface(i)
 }
 
+// Indirect returns the value that v points to.
+// If v is a nil pointer, Indirect returns a zero Value.
+// If v is not a pointer, Indirect returns v.
+func Indirect(v Value) Value {
+	if v.Kind() != Pointer {
+		return v
+	}
+	return v.Elem()
+}
+
 // arrayAt returns the i-th element of p,
 // an array whose elements are eltSize bytes wide.
 // The array pointed at by p must have at least i+1 elements: