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Diffstat (limited to 'test/typeparam/map.go')
-rw-r--r-- | test/typeparam/map.go | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/test/typeparam/map.go b/test/typeparam/map.go new file mode 100644 index 0000000..eb68fe5 --- /dev/null +++ b/test/typeparam/map.go @@ -0,0 +1,39 @@ +// 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" + "reflect" + "strconv" +) + +// Map calls the function f on every element of the slice s, +// returning a new slice of the results. +func mapper[F, T any](s []F, f func(F) T) []T { + r := make([]T, len(s)) + for i, v := range s { + r[i] = f(v) + } + return r +} + +func main() { + got := mapper([]int{1, 2, 3}, strconv.Itoa) + want := []string{"1", "2", "3"} + if !reflect.DeepEqual(got, want) { + panic(fmt.Sprintf("got %s, want %s", got, want)) + } + + fgot := mapper([]float64{2.5, 2.3, 3.5}, func(f float64) string { + return strconv.FormatFloat(f, 'f', -1, 64) + }) + fwant := []string{"2.5", "2.3", "3.5"} + if !reflect.DeepEqual(fgot, fwant) { + panic(fmt.Sprintf("got %s, want %s", fgot, fwant)) + } +} |