reflect: implement Value.Set*() for basic types

src/reflect/type.go

@@ -199,8 +199,7 @@ func (t Type) Size() uintptr {
 	case Slice:
 		return unsafe.Sizeof(SliceHeader{})
 	default:
-		// Size unknown.
+		panic("unimplemented: size of type")
-		return 0
 	}
 }
 

src/reflect/value.go

@@ -4,22 +4,42 @@ import (
 	"unsafe"
 )
 
-// This is the same thing as an interface{}.
 type Value struct {
 	typecode Type
 	value    unsafe.Pointer
+	indirect bool
 }
 
 func Indirect(v Value) Value {
-	return v
+	if v.Kind() != Ptr {
+		return v
+	}
+	return v.Elem()
 }
 
 func ValueOf(i interface{}) Value {
-	return *(*Value)(unsafe.Pointer(&i))
+	v := (*interfaceHeader)(unsafe.Pointer(&i))
+	return Value{
+		typecode: v.typecode,
+		value:    v.value,
+	}
 }
 
 func (v Value) Interface() interface{} {
-	return *(*interface{})(unsafe.Pointer(&v))
+	i := interfaceHeader{
+		typecode: v.typecode,
+		value:    v.value,
+	}
+	if v.indirect && v.Type().Size() <= unsafe.Sizeof(uintptr(0)) {
+		// Value was indirect but must be put back directly in the interface
+		// value.
+		var value uintptr
+		for j := v.Type().Size(); j != 0; j-- {
+			value = (value << 8) | uintptr(*(*uint8)(unsafe.Pointer(uintptr(v.value) + j - 1)))
+		}
+		i.value = unsafe.Pointer(value)
+	}
+	return *(*interface{})(unsafe.Pointer(&i))
 }
 
 func (v Value) Type() Type {
@@ -47,7 +67,11 @@ func (v Value) IsNil() bool {
 		slice := (*SliceHeader)(v.value)
 		return slice.Data == 0
 	case Interface:
-		panic("unimplemented: (reflect.Value).IsNil()")
+		if v.value == nil {
+			return true
+		}
+		itf := (*interfaceHeader)(v.value)
+		return itf.value == nil
 	default:
 		panic(&ValueError{"IsNil"})
 	}
@@ -85,13 +109,17 @@ func (v Value) Addr() Value {
 }
 
 func (v Value) CanSet() bool {
-	panic("unimplemented: (reflect.Value).CanSet()")
+	return v.indirect
 }
 
 func (v Value) Bool() bool {
 	switch v.Kind() {
 	case Bool:
-		return uintptr(v.value) != 0
+		if v.indirect {
+			return *((*bool)(v.value))
+		} else {
+			return uintptr(v.value) != 0
+		}
 	default:
 		panic(&ValueError{"Bool"})
 	}
@@ -100,27 +128,34 @@ func (v Value) Bool() bool {
 func (v Value) Int() int64 {
 	switch v.Kind() {
 	case Int:
-		if unsafe.Sizeof(int(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(int(0)) > unsafe.Sizeof(uintptr(0)) {
-			return int64(int(uintptr(v.value)))
-		} else {
 			return int64(*(*int)(v.value))
+		} else {
+			return int64(int(uintptr(v.value)))
 		}
 	case Int8:
-		return int64(int8(uintptr(v.value)))
+		if v.indirect {
-	case Int16:
+			return int64(*(*int8)(v.value))
-		return int64(int16(uintptr(v.value)))
-	case Int32:
-		if unsafe.Sizeof(int32(0)) <= unsafe.Sizeof(uintptr(0)) {
-			return int64(int32(uintptr(v.value)))
 		} else {
-			return int64(*(*int32)(v.value))
+			return int64(int8(uintptr(v.value)))
 		}
-		return int64(uintptr(v.value))
+	case Int16:
-	case Int64:
+		if v.indirect {
-		if unsafe.Sizeof(int64(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return int64(*(*int16)(v.value))
-			return int64(uintptr(v.value))
 		} else {
-			return *(*int64)(v.value)
+			return int64(int16(uintptr(v.value)))
+		}
+	case Int32:
+		if v.indirect || unsafe.Sizeof(int32(0)) > unsafe.Sizeof(uintptr(0)) {
+			return int64(*(*int32)(v.value))
+		} else {
+			return int64(int32(uintptr(v.value)))
+		}
+	case Int64:
+		if v.indirect || unsafe.Sizeof(int64(0)) > unsafe.Sizeof(uintptr(0)) {
+			return int64(*(*int64)(v.value))
+		} else {
+			return int64(int64(uintptr(v.value)))
 		}
 	default:
 		panic(&ValueError{"Int"})
@@ -129,28 +164,41 @@ func (v Value) Int() int64 {
 
 func (v Value) Uint() uint64 {
 	switch v.Kind() {
-	case Uintptr, Uint8, Uint16:
+	case Uintptr:
-		return uint64(uintptr(v.value))
+		if v.indirect {
-	case Uint:
+			return uint64(*(*uintptr)(v.value))
-		if unsafe.Sizeof(uint(0)) <= unsafe.Sizeof(uintptr(0)) {
-			return uint64(uintptr(v.value))
 		} else {
-			// For systems with 16-bit pointers.
+			return uint64(uintptr(v.value))
+		}
+	case Uint8:
+		if v.indirect {
+			return uint64(*(*uint8)(v.value))
+		} else {
+			return uint64(uintptr(v.value))
+		}
+	case Uint16:
+		if v.indirect {
+			return uint64(*(*uint16)(v.value))
+		} else {
+			return uint64(uintptr(v.value))
+		}
+	case Uint:
+		if v.indirect || unsafe.Sizeof(uint(0)) > unsafe.Sizeof(uintptr(0)) {
 			return uint64(*(*uint)(v.value))
+		} else {
+			return uint64(uintptr(v.value))
 		}
 	case Uint32:
-		if unsafe.Sizeof(uint32(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(uint32(0)) > unsafe.Sizeof(uintptr(0)) {
-			return uint64(uintptr(v.value))
-		} else {
-			// For systems with 16-bit pointers.
 			return uint64(*(*uint32)(v.value))
+		} else {
+			return uint64(uintptr(v.value))
 		}
 	case Uint64:
-		if unsafe.Sizeof(uint64(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(uint64(0)) > unsafe.Sizeof(uintptr(0)) {
-			return uint64(uintptr(v.value))
+			return uint64(*(*uint64)(v.value))
 		} else {
-			// For systems with 16-bit or 32-bit pointers.
+			return uint64(uintptr(v.value))
-			return *(*uint64)(v.value)
 		}
 	default:
 		panic(&ValueError{"Uint"})
@@ -160,23 +208,23 @@ func (v Value) Uint() uint64 {
 func (v Value) Float() float64 {
 	switch v.Kind() {
 	case Float32:
-		if unsafe.Sizeof(float32(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(float32(0)) > unsafe.Sizeof(uintptr(0)) {
-			// The float is directly stored in the interface value on systems
-			// with 32-bit and 64-bit pointers.
-			return float64(*(*float32)(unsafe.Pointer(&v.value)))
-		} else {
 			// The float is stored as an external value on systems with 16-bit
 			// pointers.
 			return float64(*(*float32)(v.value))
+		} else {
+			// The float is directly stored in the interface value on systems
+			// with 32-bit and 64-bit pointers.
+			return float64(*(*float32)(unsafe.Pointer(&v.value)))
 		}
 	case Float64:
-		if unsafe.Sizeof(float64(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(float64(0)) > unsafe.Sizeof(uintptr(0)) {
+			// For systems with 16-bit and 32-bit pointers.
+			return *(*float64)(v.value)
+		} else {
 			// The float is directly stored in the interface value on systems
 			// with 64-bit pointers.
 			return *(*float64)(unsafe.Pointer(&v.value))
-		} else {
-			// For systems with 16-bit and 32-bit pointers.
-			return *(*float64)(v.value)
 		}
 	default:
 		panic(&ValueError{"Float"})
@@ -186,14 +234,14 @@ func (v Value) Float() float64 {
 func (v Value) Complex() complex128 {
 	switch v.Kind() {
 	case Complex64:
-		if unsafe.Sizeof(complex64(0)) <= unsafe.Sizeof(uintptr(0)) {
+		if v.indirect || unsafe.Sizeof(complex64(0)) > unsafe.Sizeof(uintptr(0)) {
-			// The complex number is directly stored in the interface value on
-			// systems with 64-bit pointers.
-			return complex128(*(*complex64)(unsafe.Pointer(&v.value)))
-		} else {
 			// The complex number is stored as an external value on systems with
 			// 16-bit and 32-bit pointers.
 			return complex128(*(*complex64)(v.value))
+		} else {
+			// The complex number is directly stored in the interface value on
+			// systems with 64-bit pointers.
+			return complex128(*(*complex64)(unsafe.Pointer(&v.value)))
 		}
 	case Complex128:
 		// This is a 128-bit value, which is always stored as an external value.
@@ -252,7 +300,23 @@ func (v Value) NumField() int {
 }
 
 func (v Value) Elem() Value {
-	panic("unimplemented: (reflect.Value).Elem()")
+	switch v.Kind() {
+	case Ptr:
+		ptr := v.value
+		if v.indirect {
+			ptr = *(*unsafe.Pointer)(ptr)
+		}
+		if ptr == nil {
+			return Value{}
+		}
+		return Value{
+			typecode: v.Type().Elem(),
+			value:    ptr,
+			indirect: true,
+		}
+	default: // not implemented: Interface
+		panic(&ValueError{"Elem"})
+	}
 }
 
 func (v Value) Field(i int) Value {
@@ -269,21 +333,10 @@ func (v Value) Index(i int) Value {
 		}
 		elem := Value{
 			typecode: v.Type().Elem(),
+			indirect: true,
 		}
 		addr := uintptr(slice.Data) + elem.Type().Size() * uintptr(i) // pointer to new value
-		if elem.Type().Size() <= unsafe.Sizeof(uintptr(0)) {
+		elem.value = unsafe.Pointer(addr)
-			// Value fits inside interface value.
-			// Make sure to copy it from the slice to the interface value.
-			var value uintptr
-			for j := elem.Type().Size(); j != 0; j-- {
-				value = (value << 8) | uintptr(*(*uint8)(unsafe.Pointer(addr + j - 1)))
-			}
-			elem.value = unsafe.Pointer(value)
-		} else {
-			// Value doesn't fit in the interface.
-			// Store a pointer to the element in the interface.
-			elem.value = unsafe.Pointer(addr)
-		}
 		return elem
 	case String:
 		// Extract a character from a string.
@@ -313,31 +366,117 @@ func (v Value) MapIndex(key Value) Value {
 }
 
 func (v Value) Set(x Value) {
-	panic("unimplemented: (reflect.Value).Set()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	if v.Type() != x.Type() {
+		if v.Kind() == Interface {
+			panic("reflect: unimplemented: assigning to interface of different type")
+		} else {
+			panic("reflect: cannot assign")
+		}
+	}
+	size := v.Type().Size()
+	xptr := x.value
+	if size <= unsafe.Sizeof(uintptr(0)) && !x.indirect {
+		value := x.value
+		xptr = unsafe.Pointer(&value)
+	}
+	memcpy(v.value, xptr, size)
 }
 
 func (v Value) SetBool(x bool) {
-	panic("unimplemented: (reflect.Value).SetBool()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case Bool:
+		*(*bool)(v.value) = x
+	default:
+		panic(&ValueError{"SetBool"})
+	}
 }
 
 func (v Value) SetInt(x int64) {
-	panic("unimplemented: (reflect.Value).SetInt()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case Int:
+		*(*int)(v.value) = int(x)
+	case Int8:
+		*(*int8)(v.value) = int8(x)
+	case Int16:
+		*(*int16)(v.value) = int16(x)
+	case Int32:
+		*(*int32)(v.value) = int32(x)
+	case Int64:
+		*(*int64)(v.value) = x
+	default:
+		panic(&ValueError{"SetInt"})
+	}
 }
 
 func (v Value) SetUint(x uint64) {
-	panic("unimplemented: (reflect.Value).SetUint()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case Uint:
+		*(*uint)(v.value) = uint(x)
+	case Uint8:
+		*(*uint8)(v.value) = uint8(x)
+	case Uint16:
+		*(*uint16)(v.value) = uint16(x)
+	case Uint32:
+		*(*uint32)(v.value) = uint32(x)
+	case Uint64:
+		*(*uint64)(v.value) = x
+	case Uintptr:
+		*(*uintptr)(v.value) = uintptr(x)
+	default:
+		panic(&ValueError{"SetUint"})
+	}
 }
 
 func (v Value) SetFloat(x float64) {
-	panic("unimplemented: (reflect.Value).SetFloat()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case Float32:
+		*(*float32)(v.value) = float32(x)
+	case Float64:
+		*(*float64)(v.value) = x
+	default:
+		panic(&ValueError{"SetFloat"})
+	}
 }
 
 func (v Value) SetComplex(x complex128) {
-	panic("unimplemented: (reflect.Value).SetComplex()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case Complex64:
+		*(*complex64)(v.value) = complex64(x)
+	case Complex128:
+		*(*complex128)(v.value) = x
+	default:
+		panic(&ValueError{"SetComplex"})
+	}
 }
 
 func (v Value) SetString(x string) {
-	panic("unimplemented: (reflect.Value).SetString()")
+	if !v.indirect {
+		panic("reflect: value is not addressable")
+	}
+	switch v.Kind() {
+	case String:
+		*(*string)(v.value) = x
+	default:
+		panic(&ValueError{"SetString"})
+	}
 }
 
 func MakeSlice(typ Type, len, cap int) Value {
@@ -349,6 +488,12 @@ type funcHeader struct {
 	Code    unsafe.Pointer
 }
 
+// This is the same thing as an interface{}.
+type interfaceHeader struct {
+	typecode Type
+	value    unsafe.Pointer
+}
+
 type SliceHeader struct {
 	Data uintptr
 	Len  uintptr
@@ -367,3 +512,6 @@ type ValueError struct {
 func (e *ValueError) Error() string {
 	return "reflect: call of reflect.Value." + e.Method + " on invalid type"
 }
+
+//go:linkname memcpy runtime.memcpy
+func memcpy(dst, src unsafe.Pointer, size uintptr)

testdata/reflect.go

@@ -66,6 +66,10 @@ func main() {
 		[]string{"xyz", "Z"},
 		zeroSlice,
 		[]byte{},
+		[]float32{1, 1.32},
+		[]float64{1, 1.64},
+		[]complex64{1, 1.64 + 0.3i},
+		[]complex128{1, 1.128 + 0.4i},
 		// array
 		[4]int{1, 2, 3, 4},
 		// functions
@@ -78,7 +82,7 @@ func main() {
 		struct{}{},
 		struct{ error }{},
 	} {
-		showValue(v, "")
+		showValue(reflect.ValueOf(v), "")
 	}
 
 	// test sizes
@@ -98,24 +102,136 @@ func main() {
 	assertSize(reflect.TypeOf(uintptr(0)).Size() == unsafe.Sizeof(uintptr(0)), "uintptr")
 	assertSize(reflect.TypeOf("").Size() == unsafe.Sizeof(""), "string")
 	assertSize(reflect.TypeOf(new(int)).Size() == unsafe.Sizeof(new(int)), "*int")
+
+	// SetBool
+	rv := reflect.ValueOf(new(bool)).Elem()
+	rv.SetBool(true)
+	if rv.Bool() != true {
+		panic("could not set bool with SetBool()")
+	}
+
+	// SetInt
+	for _, v := range []interface{}{
+		new(int),
+		new(int8),
+		new(int16),
+		new(int32),
+		new(int64),
+	} {
+		rv := reflect.ValueOf(v).Elem()
+		rv.SetInt(99)
+		if rv.Int() != 99 {
+			panic("could not set integer with SetInt()")
+		}
+	}
+
+	// SetUint
+	for _, v := range []interface{}{
+		new(uint),
+		new(uint8),
+		new(uint16),
+		new(uint32),
+		new(uint64),
+		new(uintptr),
+	} {
+		rv := reflect.ValueOf(v).Elem()
+		rv.SetUint(99)
+		if rv.Uint() != 99 {
+			panic("could not set integer with SetUint()")
+		}
+	}
+
+	// SetFloat
+	for _, v := range []interface{}{
+		new(float32),
+		new(float64),
+	} {
+		rv := reflect.ValueOf(v).Elem()
+		rv.SetFloat(2.25)
+		if rv.Float() != 2.25 {
+			panic("could not set float with SetFloat()")
+		}
+	}
+
+	// SetComplex
+	for _, v := range []interface{}{
+		new(complex64),
+		new(complex128),
+	} {
+		rv := reflect.ValueOf(v).Elem()
+		rv.SetComplex(3 + 2i)
+		if rv.Complex() != 3+2i {
+			panic("could not set complex with SetComplex()")
+		}
+	}
+
+	// SetString
+	rv = reflect.ValueOf(new(string)).Elem()
+	rv.SetString("foo")
+	if rv.String() != "foo" {
+		panic("could not set string with SetString()")
+	}
+
+	// Set int
+	rv = reflect.ValueOf(new(int)).Elem()
+	rv.SetInt(33)
+	rv.Set(reflect.ValueOf(22))
+	if rv.Int() != 22 {
+		panic("could not set int with Set()")
+	}
+
+	// Set uint8
+	rv = reflect.ValueOf(new(uint8)).Elem()
+	rv.SetUint(33)
+	rv.Set(reflect.ValueOf(uint8(22)))
+	if rv.Uint() != 22 {
+		panic("could not set uint8 with Set()")
+	}
+
+	// Set string
+	rv = reflect.ValueOf(new(string)).Elem()
+	rv.SetString("foo")
+	rv.Set(reflect.ValueOf("bar"))
+	if rv.String() != "bar" {
+		panic("could not set string with Set()")
+	}
+
+	// Set complex128
+	rv = reflect.ValueOf(new(complex128)).Elem()
+	rv.SetComplex(3 + 2i)
+	rv.Set(reflect.ValueOf(4 + 8i))
+	if rv.Complex() != 4+8i {
+		panic("could not set complex128 with Set()")
+	}
+
+	// Set to slice
+	rv = reflect.ValueOf([]int{3, 5})
+	rv.Index(1).SetInt(7)
+	if rv.Index(1).Int() != 7 {
+		panic("could not set int in slice")
+	}
+	rv.Index(1).Set(reflect.ValueOf(8))
+	if rv.Index(1).Int() != 8 {
+		panic("could not set int in slice")
+	}
+	if rv.Len() != 2 || rv.Index(0).Int() != 3 {
+		panic("slice was changed while setting part of it")
+	}
 }
 
 func emptyFunc() {
 }
 
-func showValue(v interface{}, indent string) {
+func showValue(rv reflect.Value, indent string) {
-	rv := reflect.ValueOf(v)
 	rt := rv.Type()
-	if reflect.TypeOf(v) != rt {
-		panic("direct TypeOf() is different from ValueOf().Type()")
-	}
 	if rt.Kind() != rv.Kind() {
 		panic("type kind is different from value kind")
 	}
-	if reflect.ValueOf(rv.Interface()) != rv {
+	print(indent+"reflect type: ", rt.Kind().String())
-		panic("reflect.ValueOf(Value.Interface()) did not return the same value")
+	if rv.CanSet() {
+		print(" settable=", rv.CanSet())
 	}
-	println(indent+"reflect type:", rt.Kind().String())
+	println()
 	switch rt.Kind() {
 	case reflect.Bool:
 		println(indent+"  bool:", rv.Bool())
@@ -130,7 +246,7 @@ func showValue(v interface{}, indent string) {
 	case reflect.String:
 		println(indent+"  string:", rv.String(), rv.Len())
 		for i := 0; i < rv.Len(); i++ {
-			showValue(rv.Index(i).Interface(), indent+"  ")
+			showValue(rv.Index(i), indent+"  ")
 		}
 	case reflect.UnsafePointer:
 		println(indent+"  pointer:", rv.Pointer() != 0)
@@ -142,19 +258,25 @@ func showValue(v interface{}, indent string) {
 	case reflect.Func:
 		println(indent + "  func")
 		println(indent+"  nil:", rv.IsNil())
+	case reflect.Interface:
+		println(indent + "  interface")
+		println(indent+"  nil:", rv.IsNil())
 	case reflect.Map:
 		println(indent + "  map")
 		println(indent+"  nil:", rv.IsNil())
 	case reflect.Ptr:
 		println(indent+"  pointer:", rv.Pointer() != 0, rt.Elem().Kind().String())
 		println(indent+"  nil:", rv.IsNil())
+		if !rv.IsNil() {
+			showValue(rv.Elem(), indent+"  ")
+		}
 	case reflect.Slice:
 		println(indent+"  slice:", rt.Elem().Kind().String(), rv.Len(), rv.Cap())
 		println(indent+"  pointer:", rv.Pointer() != 0)
 		println(indent+"  nil:", rv.IsNil())
 		for i := 0; i < rv.Len(); i++ {
 			println(indent+"  indexing:", i)
-			showValue(rv.Index(i).Interface(), indent+"  ")
+			showValue(rv.Index(i), indent+"  ")
 		}
 	case reflect.Struct:
 		println(indent + "  struct")

testdata/reflect.txt

@@ -69,51 +69,58 @@ reflect type: chan
 reflect type: ptr
   pointer: true int
   nil: false
+  reflect type: int settable=true
+    int: 0
 reflect type: ptr
   pointer: true interface
   nil: false
+  reflect type: interface settable=true
+    interface
+    nil: true
 reflect type: ptr
   pointer: true int
   nil: false
+  reflect type: int settable=true
+    int: 42
 reflect type: slice
   slice: uint8 3 3
   pointer: true
   nil: false
   indexing: 0
-  reflect type: uint8
+  reflect type: uint8 settable=true
     uint: 1
   indexing: 1
-  reflect type: uint8
+  reflect type: uint8 settable=true
     uint: 2
   indexing: 2
-  reflect type: uint8
+  reflect type: uint8 settable=true
     uint: 3
 reflect type: slice
   slice: uint8 2 5
   pointer: true
   nil: false
   indexing: 0
-  reflect type: uint8
+  reflect type: uint8 settable=true
     uint: 0
   indexing: 1
-  reflect type: uint8
+  reflect type: uint8 settable=true
     uint: 0
 reflect type: slice
   slice: int32 2 2
   pointer: true
   nil: false
   indexing: 0
-  reflect type: int32
+  reflect type: int32 settable=true
     int: 3
   indexing: 1
-  reflect type: int32
+  reflect type: int32 settable=true
     int: 5
 reflect type: slice
   slice: string 2 2
   pointer: true
   nil: false
   indexing: 0
-  reflect type: string
+  reflect type: string settable=true
     string: xyz 3
     reflect type: uint8
       uint: 120
@@ -122,7 +129,7 @@ reflect type: slice
     reflect type: uint8
       uint: 122
   indexing: 1
-  reflect type: string
+  reflect type: string settable=true
     string: Z 1
     reflect type: uint8
       uint: 90
@@ -134,6 +141,46 @@ reflect type: slice
   slice: uint8 0 0
   pointer: true
   nil: false
+reflect type: slice
+  slice: float32 2 2
+  pointer: true
+  nil: false
+  indexing: 0
+  reflect type: float32 settable=true
+    float: +1.000000e+000
+  indexing: 1
+  reflect type: float32 settable=true
+    float: +1.320000e+000
+reflect type: slice
+  slice: float64 2 2
+  pointer: true
+  nil: false
+  indexing: 0
+  reflect type: float64 settable=true
+    float: +1.000000e+000
+  indexing: 1
+  reflect type: float64 settable=true
+    float: +1.640000e+000
+reflect type: slice
+  slice: complex64 2 2
+  pointer: true
+  nil: false
+  indexing: 0
+  reflect type: complex64 settable=true
+    complex: (+1.000000e+000+0.000000e+000i)
+  indexing: 1
+  reflect type: complex64 settable=true
+    complex: (+1.640000e+000+3.000000e-001i)
+reflect type: slice
+  slice: complex128 2 2
+  pointer: true
+  nil: false
+  indexing: 0
+  reflect type: complex128 settable=true
+    complex: (+1.000000e+000+0.000000e+000i)
+  indexing: 1
+  reflect type: complex128 settable=true
+    complex: (+1.128000e+000+4.000000e-001i)
 reflect type: array
   array
 reflect type: func