diff options
Diffstat (limited to 'test/typeparam/index.go')
-rw-r--r-- | test/typeparam/index.go | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/test/typeparam/index.go b/test/typeparam/index.go new file mode 100644 index 0000000..064d33c --- /dev/null +++ b/test/typeparam/index.go @@ -0,0 +1,81 @@ +// run + +// 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. + +package main + +import ( + "fmt" +) + +// Index returns the index of x in s, or -1 if not found. +func Index[T comparable](s []T, x T) int { + for i, v := range s { + // v and x are type T, which has the comparable + // constraint, so we can use == here. + if v == x { + return i + } + } + return -1 +} + +type obj struct { + x int +} + +type obj2 struct { + x int8 + y float64 +} + +type obj3 struct { + x int64 + y int8 +} + +type inner struct { + y int64 + z int32 +} + +type obj4 struct { + x int32 + s inner +} + +func main() { + want := 2 + + vec1 := []string{"ab", "cd", "ef"} + if got := Index(vec1, "ef"); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } + + vec2 := []byte{'c', '6', '@'} + if got := Index(vec2, '@'); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } + + vec3 := []*obj{&obj{2}, &obj{42}, &obj{1}} + if got := Index(vec3, vec3[2]); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } + + vec4 := []obj2{obj2{2, 3.0}, obj2{3, 4.0}, obj2{4, 5.0}} + if got := Index(vec4, vec4[2]); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } + + vec5 := []obj3{obj3{2, 3}, obj3{3, 4}, obj3{4, 5}} + if got := Index(vec5, vec5[2]); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } + + vec6 := []obj4{obj4{2, inner{3, 4}}, obj4{3, inner{4, 5}}, obj4{4, inner{5, 6}}} + if got := Index(vec6, vec6[2]); got != want { + panic(fmt.Sprintf("got %d, want %d", got, want)) + } +} |