go/test/typeparam/tparam1.go
Robert Griesemer 3d8453e00e [dev.typeparams] cmd/compile/internal/types2: more consistent handling of predeclared "any"
Rather than removing "any" from the universe scope, keep it predeclared
but provide a better error message.

While at it, remove some unnecessary type assertions.

Change-Id: I10603274282ea6afc107f703ab194f32bd334dd1
Reviewed-on: https://go-review.googlesource.com/c/go/+/334911
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-07-16 04:41:47 +00:00

42 lines
1.1 KiB
Go

// errorcheck -G
// Copyright 2020 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.
// Basic type parameter list type-checking (not syntax) errors.
package tparam1
// The predeclared identifier "any" is only visible as a constraint
// in a type parameter list.
var _ any // ERROR "cannot use any outside constraint position"
func _(_ any) // ERROR "cannot use any outside constraint position"
type _[_ any /* ok here */ ] struct{}
const N = 10
type (
_[] struct{} // slice
_[N] struct{} // array
_[T any] struct{}
_[T, T any] struct{} // ERROR "T redeclared"
_[T1, T2 any, T3 any] struct{}
)
func _[T any]()
func _[T, T any]() // ERROR "T redeclared"
func _[T1, T2 any](x T1) T2
// Type parameters are visible from opening [ to end of function.
type C interface{}
func _[T interface{}]()
func _[T C]()
func _[T struct{}]() // ERROR "not an interface"
func _[T interface{ m() T }]()
func _[T1 interface{ m() T2 }, T2 interface{ m() T1 }]() {
var _ T1
}
// TODO(gri) expand this