constraints: remove Slice/Map/Chan
Now that we permit arbitrary types as constraints, we no longer need them.
For #48424
Change-Id: I15fef26a563988074650cb0801895b002c44148a
Reviewed-on: https://go-review.googlesource.com/c/go/+/359258
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
diff --git a/src/constraints/constraints.go b/src/constraints/constraints.go
index 2a5f673..2c033df 100644
--- a/src/constraints/constraints.go
+++ b/src/constraints/constraints.go
@@ -48,18 +48,3 @@
type Ordered interface {
Integer | Float | ~string
}
-
-// Slice is a constraint that matches slices of any element type.
-type Slice[Elem any] interface {
- ~[]Elem
-}
-
-// Map is a constraint that matches maps of any element and value type.
-type Map[Key comparable, Val any] interface {
- ~map[Key]Val
-}
-
-// Chan is a constraint that matches channels of any element type.
-type Chan[Elem any] interface {
- ~chan Elem
-}
diff --git a/src/constraints/constraints_test.go b/src/constraints/constraints_test.go
index db5a957..538dc84 100644
--- a/src/constraints/constraints_test.go
+++ b/src/constraints/constraints_test.go
@@ -15,15 +15,12 @@
)
type (
- testSigned[T Signed] struct{ f T }
- testUnsigned[T Unsigned] struct{ f T }
- testInteger[T Integer] struct{ f T }
- testFloat[T Float] struct{ f T }
- testComplex[T Complex] struct{ f T }
- testOrdered[T Ordered] struct{ f T }
- testSlice[T Slice[E], E any] struct{ f T }
- testMap[T Map[K, V], K comparable, V any] struct{ f T }
- testChan[T Chan[E], E any] struct{ f T }
+ testSigned[T Signed] struct{ f T }
+ testUnsigned[T Unsigned] struct{ f T }
+ testInteger[T Integer] struct{ f T }
+ testFloat[T Float] struct{ f T }
+ testComplex[T Complex] struct{ f T }
+ testOrdered[T Ordered] struct{ f T }
)
// TestTypes passes if it compiles.
@@ -40,35 +37,6 @@
_ testOrdered[int]
_ testOrdered[float64]
_ testOrdered[string]
- _ testSlice[[]int, int]
- _ testMap[map[int]bool, int, bool]
- _ testChan[chan int, int]
-}
-
-func infer1[S Slice[E], E any](s S, v E) S { return s }
-func infer2[M Map[K, V], K comparable, V any](m M, k K, v V) M { return m }
-func infer3[C Chan[E], E any](c C, v E) C { return c }
-
-func TestInference(t *testing.T) {
- var empty interface{}
-
- type S []int
- empty = infer1(S{}, 0)
- if _, ok := empty.(S); !ok {
- t.Errorf("infer1(S) returned %T, expected S", empty)
- }
-
- type M map[int]bool
- empty = infer2(M{}, 0, false)
- if _, ok := empty.(M); !ok {
- t.Errorf("infer2(M) returned %T, expected M", empty)
- }
-
- type C chan bool
- empty = infer3(make(C), true)
- if _, ok := empty.(C); !ok {
- t.Errorf("infer3(C) returned %T, expected C", empty)
- }
}
var prolog = []byte(`
@@ -77,15 +45,12 @@
import "constraints"
type (
- testSigned[T constraints.Signed] struct{ f T }
- testUnsigned[T constraints.Unsigned] struct{ f T }
- testInteger[T constraints.Integer] struct{ f T }
- testFloat[T constraints.Float] struct{ f T }
- testComplex[T constraints.Complex] struct{ f T }
- testOrdered[T constraints.Ordered] struct{ f T }
- testSlice[T constraints.Slice[E], E any] struct{ f T }
- testMap[T constraints.Map[K, V], K comparable, V any] struct{ f T }
- testChan[T constraints.Chan[E], E any] struct{ f T }
+ testSigned[T constraints.Signed] struct{ f T }
+ testUnsigned[T constraints.Unsigned] struct{ f T }
+ testInteger[T constraints.Integer] struct{ f T }
+ testFloat[T constraints.Float] struct{ f T }
+ testComplex[T constraints.Complex] struct{ f T }
+ testOrdered[T constraints.Ordered] struct{ f T }
)
`)
@@ -115,9 +80,6 @@
{"testFloat", "int8"},
{"testComplex", "float64"},
{"testOrdered", "bool"},
- {"testSlice", "int, int"},
- {"testMap", "string, string, string"},
- {"testChan", "[]int, int"},
} {
i := i
test := test
diff --git a/test/typeparam/issue48609.go b/test/typeparam/issue48609.go
index 3ca9d6e..6cf6908 100644
--- a/test/typeparam/issue48609.go
+++ b/test/typeparam/issue48609.go
@@ -6,9 +6,7 @@
package p
-import "constraints"
-
-func f[T constraints.Chan[E], E any](e E) T {
+func f[T ~chan E, E any](e E) T {
ch := make(T)
go func() {
defer close(ch)
