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// 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.
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))
}
}
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