// Numeric is type bound that matches any numeric type.
// It would likely be in a constraints package in the standard library.
type Numeric interface {
- type int, int8, int16, int32, int64,
- uint, uint8, uint16, uint32, uint64, uintptr,
- float32, float64,
- complex64, complex128
+ ~int | ~int8 | ~int16 | ~int32 | ~int64 |
+ uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+ float32 | ~float64 |
+ complex64 | ~complex128
}
func DotProduct[T Numeric](s1, s2 []T) T {
// OrderedNumeric is a type bound that matches numeric types that support the < operator.
type OrderedNumeric interface {
- type int, int8, int16, int32, int64,
- uint, uint8, uint16, uint32, uint64, uintptr,
- float32, float64
+ ~int | ~int8 | ~int16 | ~int32 | ~int64 |
+ uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+ float32 | ~float64
}
// Complex is a type bound that matches the two complex types, which do not have a < operator.
type Complex interface {
- type complex64, complex128
+ ~complex64 | ~complex128
}
// OrderedAbs is a helper type that defines an Abs method for
type F[A, B any] func(A, B) (B, A)
-func min[T interface{ type int }](x, y T) T {
+func min[T interface{ ~int }](x, y T) T {
if x < y {
return x
}
return y
}
-func _[T interface{type int, float32}](x, y T) bool { return x < y }
+func _[T interface{ ~int | ~float32 }](x, y T) bool { return x < y }
func _[T any](x, y T) bool { return x /* ERROR cannot compare */ < y }
-func _[T interface{type int, float32, bool}](x, y T) bool { return x /* ERROR cannot compare */ < y }
+func _[T interface{ ~int | ~float32 | ~bool }](x, y T) bool { return x /* ERROR cannot compare */ < y }
func _[T C1[T]](x, y T) bool { return x /* ERROR cannot compare */ < y }
func _[T C2[T]](x, y T) bool { return x < y }
type C1[T any] interface{}
-type C2[T any] interface{ type int, float32 }
+type C2[T any] interface{ ~int | ~float32 }
func new[T any]() *T {
var x T
// indexing
func _[T any] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type int }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type string }] (x T, i int) { _ = x[i] }
-func _[T interface{ type []int }] (x T, i int) { _ = x[i] }
-func _[T interface{ type [10]int, *[20]int, map[string]int }] (x T, i int) { _ = x[i] }
-func _[T interface{ type string, []byte }] (x T, i int) { _ = x[i] }
-func _[T interface{ type []int, [1]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type string, []rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~int }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~string }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[]int }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[10]int | ~*[20]int | ~map[string]int }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~string | ~[]byte }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[]int | ~[1]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~string | ~[]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
// slicing
// TODO(gri) implement this
-func _[T interface{ type string }] (x T, i, j, k int) { _ = x /* ERROR invalid operation */ [i:j:k] }
+func _[T interface{ ~string }] (x T, i, j, k int) { _ = x /* ERROR invalid operation */ [i:j:k] }
// len/cap built-ins
func _[T any](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string, []byte, int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string }](x T) { _ = len(x) }
-func _[T interface{ type [10]int }](x T) { _ = len(x) }
-func _[T interface{ type []byte }](x T) { _ = len(x) }
-func _[T interface{ type map[int]int }](x T) { _ = len(x) }
-func _[T interface{ type chan int }](x T) { _ = len(x) }
-func _[T interface{ type string, []byte, chan int }](x T) { _ = len(x) }
+func _[T interface{ ~int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string | ~[]byte | ~int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string }](x T) { _ = len(x) }
+func _[T interface{ ~[10]int }](x T) { _ = len(x) }
+func _[T interface{ ~[]byte }](x T) { _ = len(x) }
+func _[T interface{ ~map[int]int }](x T) { _ = len(x) }
+func _[T interface{ ~chan int }](x T) { _ = len(x) }
+func _[T interface{ ~string | ~[]byte | ~chan int }](x T) { _ = len(x) }
func _[T any](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string, []byte, int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type [10]int }](x T) { _ = cap(x) }
-func _[T interface{ type []byte }](x T) { _ = cap(x) }
-func _[T interface{ type map[int]int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type chan int }](x T) { _ = cap(x) }
-func _[T interface{ type []byte, chan int }](x T) { _ = cap(x) }
+func _[T interface{ ~int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string | ~[]byte | ~int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~[10]int }](x T) { _ = cap(x) }
+func _[T interface{ ~[]byte }](x T) { _ = cap(x) }
+func _[T interface{ ~map[int]int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~chan int }](x T) { _ = cap(x) }
+func _[T interface{ ~[]byte | ~chan int }](x T) { _ = cap(x) }
// range iteration
for range x /* ERROR cannot range */ {}
}
-func _[T interface{ type string, []string }](x T) {
+func _[T interface{ ~string | ~[]string }](x T) {
for range x {}
for i := range x { _ = i }
for i, _ := range x { _ = i }
}
-func _[T interface{ type string, []rune, map[int]rune }](x T) {
+func _[T interface{ ~string | ~[]rune | ~map[int]rune }](x T) {
for _, e := range x { _ = e }
for i, e := range x { _ = i; _ = e }
}
-func _[T interface{ type string, []rune, map[string]rune }](x T) {
+func _[T interface{ ~string | ~[]rune | ~map[string]rune }](x T) {
for _, e := range x { _ = e }
for i, e := range x /* ERROR must have the same key type */ { _ = e }
}
-func _[T interface{ type string, chan int }](x T) {
+func _[T interface{ ~string | ~chan int }](x T) {
for range x {}
for i := range x { _ = i }
for i, _ := range x { _ = i } // TODO(gri) should get an error here: channels only return one value
}
-func _[T interface{ type string, chan<-int }](x T) {
+func _[T interface{ ~string | ~chan<-int }](x T) {
for i := range x /* ERROR send-only channel */ { _ = i }
}
}
}
-func _[T interface{type int}](x T) {
+func _[T interface{ ~int }](x T) {
_ = x /* ERROR not an interface */ .(int)
switch x /* ERROR not an interface */ .(type) {
}