package main import ( "bytes" "fmt" "io" "math" "reflect" "strings" "unsafe" ) type Value struct { typ_ unsafe.Pointer ptr unsafe.Pointer flag uintptr } const flagStickyRO uintptr = 1 << 5 // MakeRO returns a copy of v with the read-only flag set. func MakeRO(v reflect.Value) reflect.Value { (*Value)(unsafe.Pointer(&v)).flag |= flagStickyRO return v } // IsRO reports whether v's read-only flag is set. func IsRO(v reflect.Value) bool { return (*Value)(unsafe.Pointer(&v)).flag&flagStickyRO != 0 } type testingT struct { } func (t *testingT) Errorf(format string, a ...interface{}) { panic(fmt.Sprintf(format, a...)) } func (t *testingT) Fatalf(format string, a ...interface{}) { panic(fmt.Sprintf(format, a...)) } func main() { TestConvert(&testingT{}) TestConvertPanic(&testingT{}) TestConvertSlice2Array(&testingT{}) TestConvertNaNs(&testingT{}) } var V = reflect.ValueOf func EmptyInterfaceV(x any) reflect.Value { return V(&x).Elem() } func ReaderV(x io.Reader) reflect.Value { return V(&x).Elem() } func ReadWriterV(x io.ReadWriter) reflect.Value { return V(&x).Elem() } type integer int type T struct { a int b float64 c string d *int } type Empty struct{} type MyStruct struct { x int `some:"tag"` } type MyStruct1 struct { x struct { int `some:"bar"` } } type MyStruct2 struct { x struct { int `some:"foo"` } } type MyString string type MyBytes []byte type MyBytesArrayPtr0 *[0]byte type MyBytesArrayPtr *[4]byte type MyBytesArray0 [0]byte type MyBytesArray [4]byte type MyRunes []int32 type MyFunc func() type MyByte byte type IntChan chan int type IntChanRecv <-chan int type IntChanSend chan<- int type BytesChan chan []byte type BytesChanRecv <-chan []byte type BytesChanSend chan<- []byte var convertTests = []struct { in reflect.Value out reflect.Value }{ // numbers /* Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go package main import "fmt" var numbers = []string{ "int8", "uint8", "int16", "uint16", "int32", "uint32", "int64", "uint64", "int", "uint", "uintptr", "float32", "float64", } func main() { // all pairs but in an unusual order, // to emit all the int8, uint8 cases // before n grows too big. n := 1 for i, f := range numbers { for _, g := range numbers[i:] { fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n) n++ if f != g { fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n) n++ } } } } */ {V(int8(1)), V(int8(1))}, {V(int8(2)), V(uint8(2))}, {V(uint8(3)), V(int8(3))}, {V(int8(4)), V(int16(4))}, {V(int16(5)), V(int8(5))}, {V(int8(6)), V(uint16(6))}, {V(uint16(7)), V(int8(7))}, {V(int8(8)), V(int32(8))}, {V(int32(9)), V(int8(9))}, {V(int8(10)), V(uint32(10))}, {V(uint32(11)), V(int8(11))}, {V(int8(12)), V(int64(12))}, {V(int64(13)), V(int8(13))}, {V(int8(14)), V(uint64(14))}, {V(uint64(15)), V(int8(15))}, {V(int8(16)), V(int(16))}, {V(int(17)), V(int8(17))}, {V(int8(18)), V(uint(18))}, {V(uint(19)), V(int8(19))}, {V(int8(20)), V(uintptr(20))}, {V(uintptr(21)), V(int8(21))}, {V(int8(22)), V(float32(22))}, {V(float32(23)), V(int8(23))}, {V(int8(24)), V(float64(24))}, {V(float64(25)), V(int8(25))}, {V(uint8(26)), V(uint8(26))}, {V(uint8(27)), V(int16(27))}, {V(int16(28)), V(uint8(28))}, {V(uint8(29)), V(uint16(29))}, {V(uint16(30)), V(uint8(30))}, {V(uint8(31)), V(int32(31))}, {V(int32(32)), V(uint8(32))}, {V(uint8(33)), V(uint32(33))}, {V(uint32(34)), V(uint8(34))}, {V(uint8(35)), V(int64(35))}, {V(int64(36)), V(uint8(36))}, {V(uint8(37)), V(uint64(37))}, {V(uint64(38)), V(uint8(38))}, {V(uint8(39)), V(int(39))}, {V(int(40)), V(uint8(40))}, {V(uint8(41)), V(uint(41))}, {V(uint(42)), V(uint8(42))}, {V(uint8(43)), V(uintptr(43))}, {V(uintptr(44)), V(uint8(44))}, {V(uint8(45)), V(float32(45))}, {V(float32(46)), V(uint8(46))}, {V(uint8(47)), V(float64(47))}, {V(float64(48)), V(uint8(48))}, {V(int16(49)), V(int16(49))}, {V(int16(50)), V(uint16(50))}, {V(uint16(51)), V(int16(51))}, {V(int16(52)), V(int32(52))}, {V(int32(53)), V(int16(53))}, {V(int16(54)), V(uint32(54))}, {V(uint32(55)), V(int16(55))}, {V(int16(56)), V(int64(56))}, {V(int64(57)), V(int16(57))}, {V(int16(58)), V(uint64(58))}, {V(uint64(59)), V(int16(59))}, {V(int16(60)), V(int(60))}, {V(int(61)), V(int16(61))}, {V(int16(62)), V(uint(62))}, {V(uint(63)), V(int16(63))}, {V(int16(64)), V(uintptr(64))}, {V(uintptr(65)), V(int16(65))}, {V(int16(66)), V(float32(66))}, {V(float32(67)), V(int16(67))}, {V(int16(68)), V(float64(68))}, {V(float64(69)), V(int16(69))}, {V(uint16(70)), V(uint16(70))}, {V(uint16(71)), V(int32(71))}, {V(int32(72)), V(uint16(72))}, {V(uint16(73)), V(uint32(73))}, {V(uint32(74)), V(uint16(74))}, {V(uint16(75)), V(int64(75))}, {V(int64(76)), V(uint16(76))}, {V(uint16(77)), V(uint64(77))}, {V(uint64(78)), V(uint16(78))}, {V(uint16(79)), V(int(79))}, {V(int(80)), V(uint16(80))}, {V(uint16(81)), V(uint(81))}, {V(uint(82)), V(uint16(82))}, {V(uint16(83)), V(uintptr(83))}, {V(uintptr(84)), V(uint16(84))}, {V(uint16(85)), V(float32(85))}, {V(float32(86)), V(uint16(86))}, {V(uint16(87)), V(float64(87))}, {V(float64(88)), V(uint16(88))}, {V(int32(89)), V(int32(89))}, {V(int32(90)), V(uint32(90))}, {V(uint32(91)), V(int32(91))}, {V(int32(92)), V(int64(92))}, {V(int64(93)), V(int32(93))}, {V(int32(94)), V(uint64(94))}, {V(uint64(95)), V(int32(95))}, {V(int32(96)), V(int(96))}, {V(int(97)), V(int32(97))}, {V(int32(98)), V(uint(98))}, {V(uint(99)), V(int32(99))}, {V(int32(100)), V(uintptr(100))}, {V(uintptr(101)), V(int32(101))}, {V(int32(102)), V(float32(102))}, {V(float32(103)), V(int32(103))}, {V(int32(104)), V(float64(104))}, {V(float64(105)), V(int32(105))}, {V(uint32(106)), V(uint32(106))}, {V(uint32(107)), V(int64(107))}, {V(int64(108)), V(uint32(108))}, {V(uint32(109)), V(uint64(109))}, {V(uint64(110)), V(uint32(110))}, {V(uint32(111)), V(int(111))}, {V(int(112)), V(uint32(112))}, {V(uint32(113)), V(uint(113))}, {V(uint(114)), V(uint32(114))}, {V(uint32(115)), V(uintptr(115))}, {V(uintptr(116)), V(uint32(116))}, {V(uint32(117)), V(float32(117))}, {V(float32(118)), V(uint32(118))}, {V(uint32(119)), V(float64(119))}, {V(float64(120)), V(uint32(120))}, {V(int64(121)), V(int64(121))}, {V(int64(122)), V(uint64(122))}, {V(uint64(123)), V(int64(123))}, {V(int64(124)), V(int(124))}, {V(int(125)), V(int64(125))}, {V(int64(126)), V(uint(126))}, {V(uint(127)), V(int64(127))}, {V(int64(128)), V(uintptr(128))}, {V(uintptr(129)), V(int64(129))}, {V(int64(130)), V(float32(130))}, {V(float32(131)), V(int64(131))}, {V(int64(132)), V(float64(132))}, {V(float64(133)), V(int64(133))}, {V(uint64(134)), V(uint64(134))}, {V(uint64(135)), V(int(135))}, {V(int(136)), V(uint64(136))}, {V(uint64(137)), V(uint(137))}, {V(uint(138)), V(uint64(138))}, {V(uint64(139)), V(uintptr(139))}, {V(uintptr(140)), V(uint64(140))}, {V(uint64(141)), V(float32(141))}, {V(float32(142)), V(uint64(142))}, {V(uint64(143)), V(float64(143))}, {V(float64(144)), V(uint64(144))}, {V(int(145)), V(int(145))}, {V(int(146)), V(uint(146))}, {V(uint(147)), V(int(147))}, {V(int(148)), V(uintptr(148))}, {V(uintptr(149)), V(int(149))}, {V(int(150)), V(float32(150))}, {V(float32(151)), V(int(151))}, {V(int(152)), V(float64(152))}, {V(float64(153)), V(int(153))}, {V(uint(154)), V(uint(154))}, {V(uint(155)), V(uintptr(155))}, {V(uintptr(156)), V(uint(156))}, {V(uint(157)), V(float32(157))}, {V(float32(158)), V(uint(158))}, {V(uint(159)), V(float64(159))}, {V(float64(160)), V(uint(160))}, {V(uintptr(161)), V(uintptr(161))}, {V(uintptr(162)), V(float32(162))}, {V(float32(163)), V(uintptr(163))}, {V(uintptr(164)), V(float64(164))}, {V(float64(165)), V(uintptr(165))}, {V(float32(166)), V(float32(166))}, {V(float32(167)), V(float64(167))}, {V(float64(168)), V(float32(168))}, {V(float64(169)), V(float64(169))}, // truncation {V(float64(1.5)), V(int(1))}, // complex {V(complex64(1i)), V(complex64(1i))}, {V(complex64(2i)), V(complex128(2i))}, {V(complex128(3i)), V(complex64(3i))}, {V(complex128(4i)), V(complex128(4i))}, // string {V(string("hello")), V(string("hello"))}, {V(string("bytes1")), V([]byte("bytes1"))}, {V([]byte("bytes2")), V(string("bytes2"))}, {V([]byte("bytes3")), V([]byte("bytes3"))}, {V(string("runes♝")), V([]rune("runes♝"))}, {V([]rune("runes♕")), V(string("runes♕"))}, {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, {V(int('a')), V(string("a"))}, {V(int8('a')), V(string("a"))}, {V(int16('a')), V(string("a"))}, {V(int32('a')), V(string("a"))}, {V(int64('a')), V(string("a"))}, {V(uint('a')), V(string("a"))}, {V(uint8('a')), V(string("a"))}, {V(uint16('a')), V(string("a"))}, {V(uint32('a')), V(string("a"))}, {V(uint64('a')), V(string("a"))}, {V(uintptr('a')), V(string("a"))}, {V(int(-1)), V(string("\uFFFD"))}, {V(int8(-2)), V(string("\uFFFD"))}, {V(int16(-3)), V(string("\uFFFD"))}, {V(int32(-4)), V(string("\uFFFD"))}, {V(int64(-5)), V(string("\uFFFD"))}, {V(int64(-1 << 32)), V(string("\uFFFD"))}, {V(int64(1 << 32)), V(string("\uFFFD"))}, {V(uint(0x110001)), V(string("\uFFFD"))}, {V(uint32(0x110002)), V(string("\uFFFD"))}, {V(uint64(0x110003)), V(string("\uFFFD"))}, {V(uint64(1 << 32)), V(string("\uFFFD"))}, {V(uintptr(0x110004)), V(string("\uFFFD"))}, // named string {V(MyString("hello")), V(string("hello"))}, {V(string("hello")), V(MyString("hello"))}, {V(string("hello")), V(string("hello"))}, {V(MyString("hello")), V(MyString("hello"))}, {V(MyString("bytes1")), V([]byte("bytes1"))}, {V([]byte("bytes2")), V(MyString("bytes2"))}, {V([]byte("bytes3")), V([]byte("bytes3"))}, {V(MyString("runes♝")), V([]rune("runes♝"))}, {V([]rune("runes♕")), V(MyString("runes♕"))}, {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, {V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, {V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, {V(int('a')), V(MyString("a"))}, {V(int8('a')), V(MyString("a"))}, {V(int16('a')), V(MyString("a"))}, {V(int32('a')), V(MyString("a"))}, {V(int64('a')), V(MyString("a"))}, {V(uint('a')), V(MyString("a"))}, {V(uint8('a')), V(MyString("a"))}, {V(uint16('a')), V(MyString("a"))}, {V(uint32('a')), V(MyString("a"))}, {V(uint64('a')), V(MyString("a"))}, {V(uintptr('a')), V(MyString("a"))}, {V(int(-1)), V(MyString("\uFFFD"))}, {V(int8(-2)), V(MyString("\uFFFD"))}, {V(int16(-3)), V(MyString("\uFFFD"))}, {V(int32(-4)), V(MyString("\uFFFD"))}, {V(int64(-5)), V(MyString("\uFFFD"))}, {V(uint(0x110001)), V(MyString("\uFFFD"))}, {V(uint32(0x110002)), V(MyString("\uFFFD"))}, {V(uint64(0x110003)), V(MyString("\uFFFD"))}, {V(uintptr(0x110004)), V(MyString("\uFFFD"))}, // named []byte {V(string("bytes1")), V(MyBytes("bytes1"))}, {V(MyBytes("bytes2")), V(string("bytes2"))}, {V(MyBytes("bytes3")), V(MyBytes("bytes3"))}, {V(MyString("bytes1")), V(MyBytes("bytes1"))}, {V(MyBytes("bytes2")), V(MyString("bytes2"))}, // named []rune {V(string("runes♝")), V(MyRunes("runes♝"))}, {V(MyRunes("runes♕")), V(string("runes♕"))}, {V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, {V(MyString("runes♝")), V(MyRunes("runes♝"))}, {V(MyRunes("runes♕")), V(MyString("runes♕"))}, // slice to array {V([]byte(nil)), V([0]byte{})}, {V([]byte{}), V([0]byte{})}, {V([]byte{1}), V([1]byte{1})}, {V([]byte{1, 2}), V([2]byte{1, 2})}, {V([]byte{1, 2, 3}), V([3]byte{1, 2, 3})}, {V(MyBytes([]byte(nil))), V([0]byte{})}, {V(MyBytes{}), V([0]byte{})}, {V(MyBytes{1}), V([1]byte{1})}, {V(MyBytes{1, 2}), V([2]byte{1, 2})}, {V(MyBytes{1, 2, 3}), V([3]byte{1, 2, 3})}, {V([]byte(nil)), V(MyBytesArray0{})}, {V([]byte{}), V(MyBytesArray0([0]byte{}))}, {V([]byte{1, 2, 3, 4}), V(MyBytesArray([4]byte{1, 2, 3, 4}))}, {V(MyBytes{}), V(MyBytesArray0([0]byte{}))}, {V(MyBytes{5, 6, 7, 8}), V(MyBytesArray([4]byte{5, 6, 7, 8}))}, {V([]MyByte{}), V([0]MyByte{})}, {V([]MyByte{1, 2}), V([2]MyByte{1, 2})}, // slice to array pointer {V([]byte(nil)), V((*[0]byte)(nil))}, {V([]byte{}), V(new([0]byte))}, {V([]byte{7}), V(&[1]byte{7})}, {V(MyBytes([]byte(nil))), V((*[0]byte)(nil))}, {V(MyBytes([]byte{})), V(new([0]byte))}, {V(MyBytes([]byte{9})), V(&[1]byte{9})}, {V([]byte(nil)), V(MyBytesArrayPtr0(nil))}, {V([]byte{}), V(MyBytesArrayPtr0(new([0]byte)))}, {V([]byte{1, 2, 3, 4}), V(MyBytesArrayPtr(&[4]byte{1, 2, 3, 4}))}, {V(MyBytes([]byte{})), V(MyBytesArrayPtr0(new([0]byte)))}, {V(MyBytes([]byte{5, 6, 7, 8})), V(MyBytesArrayPtr(&[4]byte{5, 6, 7, 8}))}, {V([]byte(nil)), V((*MyBytesArray0)(nil))}, {V([]byte{}), V((*MyBytesArray0)(new([0]byte)))}, {V([]byte{1, 2, 3, 4}), V(&MyBytesArray{1, 2, 3, 4})}, {V(MyBytes([]byte(nil))), V((*MyBytesArray0)(nil))}, {V(MyBytes([]byte{})), V((*MyBytesArray0)(new([0]byte)))}, {V(MyBytes([]byte{5, 6, 7, 8})), V(&MyBytesArray{5, 6, 7, 8})}, {V(new([0]byte)), V(new(MyBytesArray0))}, {V(new(MyBytesArray0)), V(new([0]byte))}, {V(MyBytesArrayPtr0(nil)), V((*[0]byte)(nil))}, {V((*[0]byte)(nil)), V(MyBytesArrayPtr0(nil))}, // named types and equal underlying types {V(new(int)), V(new(integer))}, {V(new(integer)), V(new(int))}, {V(Empty{}), V(struct{}{})}, {V(new(Empty)), V(new(struct{}))}, {V(struct{}{}), V(Empty{})}, {V(new(struct{})), V(new(Empty))}, {V(Empty{}), V(Empty{})}, {V(MyBytes{}), V([]byte{})}, {V([]byte{}), V(MyBytes{})}, {V((func())(nil)), V(MyFunc(nil))}, {V((MyFunc)(nil)), V((func())(nil))}, // structs with different tags {V(struct { x int `some:"foo"` }{}), V(struct { x int `some:"bar"` }{})}, {V(struct { x int `some:"bar"` }{}), V(struct { x int `some:"foo"` }{})}, {V(MyStruct{}), V(struct { x int `some:"foo"` }{})}, {V(struct { x int `some:"foo"` }{}), V(MyStruct{})}, {V(MyStruct{}), V(struct { x int `some:"bar"` }{})}, {V(struct { x int `some:"bar"` }{}), V(MyStruct{})}, {V(MyStruct1{}), V(MyStruct2{})}, {V(MyStruct2{}), V(MyStruct1{})}, // can convert *byte and *MyByte {V((*byte)(nil)), V((*MyByte)(nil))}, {V((*MyByte)(nil)), V((*byte)(nil))}, // cannot convert mismatched array sizes {V([2]byte{}), V([2]byte{})}, {V([3]byte{}), V([3]byte{})}, {V(MyBytesArray0{}), V([0]byte{})}, {V([0]byte{}), V(MyBytesArray0{})}, // cannot convert other instances {V((**byte)(nil)), V((**byte)(nil))}, {V((**MyByte)(nil)), V((**MyByte)(nil))}, {V((chan byte)(nil)), V((chan byte)(nil))}, {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, {V(([]byte)(nil)), V(([]byte)(nil))}, {V(([]MyByte)(nil)), V(([]MyByte)(nil))}, {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, {V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))}, {V((map[byte]int)(nil)), V((map[byte]int)(nil))}, {V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))}, {V([2]byte{}), V([2]byte{})}, {V([2]MyByte{}), V([2]MyByte{})}, // other {V((***int)(nil)), V((***int)(nil))}, {V((***byte)(nil)), V((***byte)(nil))}, {V((***int32)(nil)), V((***int32)(nil))}, {V((***int64)(nil)), V((***int64)(nil))}, {V((chan byte)(nil)), V((chan byte)(nil))}, {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, {V((map[int]bool)(nil)), V((map[int]bool)(nil))}, {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, {V((map[uint]bool)(nil)), V((map[uint]bool)(nil))}, {V([]uint(nil)), V([]uint(nil))}, {V([]int(nil)), V([]int(nil))}, {V(new(any)), V(new(any))}, {V(new(io.Reader)), V(new(io.Reader))}, {V(new(io.Writer)), V(new(io.Writer))}, // channels {V(IntChan(nil)), V((chan<- int)(nil))}, {V(IntChan(nil)), V((<-chan int)(nil))}, {V((chan int)(nil)), V(IntChanRecv(nil))}, {V((chan int)(nil)), V(IntChanSend(nil))}, {V(IntChanRecv(nil)), V((<-chan int)(nil))}, {V((<-chan int)(nil)), V(IntChanRecv(nil))}, {V(IntChanSend(nil)), V((chan<- int)(nil))}, {V((chan<- int)(nil)), V(IntChanSend(nil))}, {V(IntChan(nil)), V((chan int)(nil))}, {V((chan int)(nil)), V(IntChan(nil))}, {V((chan int)(nil)), V((<-chan int)(nil))}, {V((chan int)(nil)), V((chan<- int)(nil))}, {V(BytesChan(nil)), V((chan<- []byte)(nil))}, {V(BytesChan(nil)), V((<-chan []byte)(nil))}, {V((chan []byte)(nil)), V(BytesChanRecv(nil))}, {V((chan []byte)(nil)), V(BytesChanSend(nil))}, {V(BytesChanRecv(nil)), V((<-chan []byte)(nil))}, {V((<-chan []byte)(nil)), V(BytesChanRecv(nil))}, {V(BytesChanSend(nil)), V((chan<- []byte)(nil))}, {V((chan<- []byte)(nil)), V(BytesChanSend(nil))}, {V(BytesChan(nil)), V((chan []byte)(nil))}, {V((chan []byte)(nil)), V(BytesChan(nil))}, {V((chan []byte)(nil)), V((<-chan []byte)(nil))}, {V((chan []byte)(nil)), V((chan<- []byte)(nil))}, // cannot convert other instances (channels) {V(IntChan(nil)), V(IntChan(nil))}, {V(IntChanRecv(nil)), V(IntChanRecv(nil))}, {V(IntChanSend(nil)), V(IntChanSend(nil))}, {V(BytesChan(nil)), V(BytesChan(nil))}, {V(BytesChanRecv(nil)), V(BytesChanRecv(nil))}, {V(BytesChanSend(nil)), V(BytesChanSend(nil))}, // interfaces {V(int(1)), EmptyInterfaceV(int(1))}, {V(string("hello")), EmptyInterfaceV(string("hello"))}, {V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, {ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, {V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))}, } func TestConvert(t *testingT) { canConvert := map[[2]reflect.Type]bool{} all := map[reflect.Type]bool{} for _, tt := range convertTests { t1 := tt.in.Type() if !t1.ConvertibleTo(t1) { t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1) continue } t2 := tt.out.Type() if !t1.ConvertibleTo(t2) { t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2) continue } all[t1] = true all[t2] = true canConvert[[2]reflect.Type{t1, t2}] = true // vout1 represents the in value converted to the in type. v1 := tt.in if !v1.CanConvert(t1) { t.Errorf("ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t1) } vout1 := v1.Convert(t1) out1 := vout1.Interface() if vout1.Type() != tt.in.Type() || !reflect.DeepEqual(out1, tt.in.Interface()) { t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface()) } // vout2 represents the in value converted to the out type. if !v1.CanConvert(t2) { t.Errorf(" ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t2) } vout2 := v1.Convert(t2) out2 := vout2.Interface() if vout2.Type() != tt.out.Type() || !reflect.DeepEqual(out2, tt.out.Interface()) { t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface()) } if got, want := vout2.Kind(), vout2.Type().Kind(); got != want { t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) has internal kind %v want %v", tt.in.Interface(), t1, got, want) } // vout3 represents a new value of the out type, set to vout2. This makes // sure the converted value vout2 is really usable as a regular value. vout3 := reflect.New(t2).Elem() vout3.Set(vout2) out3 := vout3.Interface() if vout3.Type() != tt.out.Type() || !reflect.DeepEqual(out3, tt.out.Interface()) { t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface()) } if IsRO(v1) { t.Errorf("table entry %v is RO, should not be", v1) } if IsRO(vout1) { t.Errorf("self-conversion output %v is RO, should not be", vout1) } if IsRO(vout2) { t.Errorf("conversion output %v is RO, should not be", vout2) } if IsRO(vout3) { t.Errorf("set(conversion output) %v is RO, should not be", vout3) } if !IsRO(MakeRO(v1).Convert(t1)) { t.Errorf("RO self-conversion output %v is not RO, should be", v1) } if !IsRO(MakeRO(v1).Convert(t2)) { t.Errorf("RO conversion output %v is not RO, should be", v1) } } // Assume that of all the types we saw during the tests, // if there wasn't an explicit entry for a conversion between // a pair of types, then it's not to be allowed. This checks for // things like 'int64' converting to '*int'. for t1 := range all { for t2 := range all { expectOK := t1 == t2 || canConvert[[2]reflect.Type{t1, t2}] || t2.Kind() == reflect.Interface && t2.NumMethod() == 0 ok := t1.ConvertibleTo(t2) if ok != expectOK { t.Errorf("@(%s).ConvertibleTo(%s) = %v, want %v: %v", t1, t2, ok, expectOK, canConvert[[2]reflect.Type{t1, t2}]) } } } } func TestConvertPanic(t *testingT) { s := make([]byte, 4) p := new([8]byte) v := reflect.ValueOf(s) pt := reflect.TypeOf(p) if !v.Type().ConvertibleTo(pt) { t.Errorf("[]byte should be convertible to *[8]byte") } if v.CanConvert(pt) { t.Errorf("slice with length 4 should not be convertible to *[8]byte") } shouldPanic("reflect: cannot convert slice with length 4 to pointer to array with length 8", func() { _ = v.Convert(pt) }) if v.CanConvert(pt.Elem()) { t.Errorf("slice with length 4 should not be convertible to [8]byte") } shouldPanic("reflect: cannot convert slice with length 4 to array with length 8", func() { _ = v.Convert(pt.Elem()) }) } func TestConvertSlice2Array(t *testingT) { s := make([]int, 4) p := [4]int{} pt := reflect.TypeOf(p) ov := reflect.ValueOf(s) v := ov.Convert(pt) // Converting a slice to non-empty array needs to return // a non-addressable copy of the original memory. if v.CanAddr() { t.Fatalf("convert slice to non-empty array returns a addressable copy array") } for i := range s { ov.Index(i).Set(reflect.ValueOf(i + 1)) } for i := range s { if v.Index(i).Int() != 0 { t.Fatalf("slice (%v) mutation visible in converted result (%v)", ov, v) } } } var gFloat32 float32 const snan uint32 = 0x7f800001 func TestConvertNaNs(t *testingT) { // Test to see if a store followed by a load of a signaling NaN // maintains the signaling bit. (This used to fail on the 387 port.) gFloat32 = math.Float32frombits(snan) // runtime.Gosched() // make sure we don't optimize the store/load away if got := math.Float32bits(gFloat32); got != snan { t.Errorf("store/load of sNaN not faithful, got %x want %x", got, snan) } // Test reflect's conversion between float32s. See issue 36400. type myFloat32 float32 x := V(myFloat32(math.Float32frombits(snan))) y := x.Convert(reflect.TypeOf(float32(0))) z := y.Interface().(float32) if got := math.Float32bits(z); got != snan { t.Errorf("signaling nan conversion got %x, want %x", got, snan) } } func shouldPanic(expect string, f func()) { defer func() { r := recover() if r == nil { panic("did not panic") } if expect != "" { var s string switch r := r.(type) { case string: s = r case *reflect.ValueError: s = r.Error() default: panic(fmt.Sprintf("panicked with unexpected type %T", r)) } if !strings.HasPrefix(s, "reflect") { panic(`panic string does not start with "reflect": ` + s) } if !strings.Contains(s, expect) { panic(`panic string does not contain "` + expect + `": ` + s) } } }() f() }