1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
// run -gcflags=-G=3
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// comparisons of type parameters to interfaces
package main
func f[T comparable](t, u T) bool {
// Comparing two type parameters directly.
// (Not really testing comparisons to interfaces, but just 'cause we're here.)
return t == u
}
func g[T comparable](t T, i interface{}) bool {
// Compare type parameter value to empty interface.
return t == i
}
type I interface {
foo()
}
type C interface {
comparable
I
}
func h[T C](t T, i I) bool {
// Compare type parameter value to nonempty interface.
return t == i
}
type myint int
func (x myint) foo() {
}
func k[T comparable](t T, i interface{}) bool {
// Compare derived type value to interface.
return struct{ a, b T }{t, t} == i
}
func main() {
assert(f(3, 3))
assert(!f(3, 5))
assert(g(3, 3))
assert(!g(3, 5))
assert(h(myint(3), myint(3)))
assert(!h(myint(3), myint(5)))
type S struct{ a, b float64 }
assert(f(S{3, 5}, S{3, 5}))
assert(!f(S{3, 5}, S{4, 6}))
assert(g(S{3, 5}, S{3, 5}))
assert(!g(S{3, 5}, S{4, 6}))
assert(k(3, struct{ a, b int }{3, 3}))
assert(!k(3, struct{ a, b int }{3, 4}))
}
func assert(b bool) {
if !b {
panic("assertion failed")
}
}
|
