1 files changed, 50 insertions, 0 deletions
diff --git a/test/typeparam/sum.go b/test/typeparam/sum.go
new file mode 100644
index 0000000..25bac18
--- /dev/null
+++ b/test/typeparam/sum.go
@@ -0,0 +1,50 @@
+// 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"
+)
+
+func Sum[T interface{ int | float64 }](vec []T) T {
+	var sum T
+	for _, elt := range vec {
+		sum = sum + elt
+	}
+	return sum
+}
+
+func Abs(f float64) float64 {
+	if f < 0.0 {
+		return -f
+	}
+	return f
+}
+
+func main() {
+	vec1 := []int{3, 4}
+	vec2 := []float64{5.8, 9.6}
+	got := Sum[int](vec1)
+	want := vec1[0] + vec1[1]
+	if got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+	got = Sum(vec1)
+	if want != got {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	fwant := vec2[0] + vec2[1]
+	fgot := Sum[float64](vec2)
+	if Abs(fgot-fwant) > 1e-10 {
+		panic(fmt.Sprintf("got %f, want %f", fgot, fwant))
+	}
+	fgot = Sum(vec2)
+	if Abs(fgot-fwant) > 1e-10 {
+		panic(fmt.Sprintf("got %f, want %f", fgot, fwant))
+	}
+}