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// 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.
//go:build go1.18
// +build go1.18
package typeparams
import "fmt"
func TestBasicTypeParams[T interface{ ~int }, E error, F fmt.Formatter, S fmt.Stringer, A any](t T, e E, f F, s S, a A) {
fmt.Printf("%d", t)
fmt.Printf("%s", t) // want "wrong type.*contains ~int"
fmt.Printf("%v", t)
fmt.Printf("%d", e) // want "wrong type"
fmt.Printf("%s", e)
fmt.Errorf("%w", e)
fmt.Printf("%a", f)
fmt.Printf("%d", f)
fmt.Printf("%T", f.Format)
fmt.Printf("%p", f.Format)
fmt.Printf("%s", s)
fmt.Errorf("%w", s) // want "wrong type"
fmt.Printf("%d", a) // want "wrong type"
fmt.Printf("%s", a) // want "wrong type"
fmt.Printf("%v", a)
fmt.Printf("%T", a)
}
type Constraint interface {
~int
}
func TestNamedConstraints_Issue49597[T Constraint](t T) {
fmt.Printf("%d", t)
fmt.Printf("%s", t) // want "wrong type.*contains ~int"
}
func TestNestedTypeParams[T interface{ ~int }, S interface{ ~string }]() {
var x struct {
f int
t T
}
fmt.Printf("%d", x)
fmt.Printf("%s", x) // want "wrong type"
var y struct {
f string
t S
}
fmt.Printf("%d", y) // want "wrong type"
fmt.Printf("%s", y)
var m1 map[T]T
fmt.Printf("%d", m1)
fmt.Printf("%s", m1) // want "wrong type"
var m2 map[S]S
fmt.Printf("%d", m2) // want "wrong type"
fmt.Printf("%s", m2)
}
type R struct {
F []R
}
func TestRecursiveTypeDefinition() {
var r []R
fmt.Printf("%d", r) // No error: avoids infinite recursion.
}
func TestRecursiveTypeParams[T1 ~[]T2, T2 ~[]T1 | string, T3 ~struct{ F T3 }](t1 T1, t2 T2, t3 T3) {
// No error is reported on the following lines to avoid infinite recursion.
fmt.Printf("%s", t1)
fmt.Printf("%s", t2)
fmt.Printf("%s", t3)
}
func TestRecusivePointers[T1 ~*T2, T2 ~*T1](t1 T1, t2 T2) {
// No error: we can't determine if pointer rules apply.
fmt.Printf("%s", t1)
fmt.Printf("%s", t2)
}
func TestEmptyTypeSet[T interface {
int | string
float64
}](t T) {
fmt.Printf("%s", t) // No error: empty type set.
}
func TestPointerRules[T ~*[]int | *[2]int](t T) {
var slicePtr *[]int
var arrayPtr *[2]int
fmt.Printf("%d", slicePtr)
fmt.Printf("%d", arrayPtr)
fmt.Printf("%d", t)
}
func TestInterfacePromotion[E interface {
~int
Error() string
}, S interface {
float64
String() string
}](e E, s S) {
fmt.Printf("%d", e)
fmt.Printf("%s", e)
fmt.Errorf("%w", e)
fmt.Printf("%d", s) // want "wrong type.*contains float64"
fmt.Printf("%s", s)
fmt.Errorf("%w", s) // want "wrong type"
}
type myInt int
func TestTermReduction[T1 interface{ ~int | string }, T2 interface {
~int | string
myInt
}](t1 T1, t2 T2) {
fmt.Printf("%d", t1) // want "wrong type.*contains string"
fmt.Printf("%s", t1) // want "wrong type.*contains ~int"
fmt.Printf("%d", t2)
fmt.Printf("%s", t2) // want "wrong type.*contains typeparams.myInt"
}
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