go/test/typeparam/fact.go
Robert Griesemer a360eeb528 [dev.typeparams] cmd/compile/internal/types2: conversions to type parameters are not constant
Disabled test/typeparam/fact.go for now as there's an issue
with stenciling.

Change-Id: Ie328a217de6d7b6695737f08ef5c944bcdaabd39
Reviewed-on: https://go-review.googlesource.com/c/go/+/290471
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
2021-02-08 22:24:09 +00:00

37 lines
884 B
Go

// 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"
// TODO Stenciling doesn't do the right thing for T(1) at the moment.
func fact[T interface { type int, int64, float64 }](n T) T {
// TODO remove this return in favor of the correct computation below
return n
// if n == T(1) {
// return T(1)
// }
// return n * fact(n - T(1))
}
func main() {
// TODO change this to 120 once we can compile the function body above
const want = 5 // 120
if got := fact(5); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
if got := fact[int64](5); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
if got := fact(5.0); got != want {
panic(fmt.Sprintf("got %f, want %f", got, want))
}
}