go/test/typeparam/tparam1.go
Robert Griesemer 036245862a [dev.typeparams] cmd/compile/internal/types2: set compiler error message for undeclared variable
Change-Id: Ie2950cdc5406915935f114bfd97ef03d965f9069
Reviewed-on: https://go-review.googlesource.com/c/go/+/274616
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-12-02 04:48:13 +00:00

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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 "undefined"
func _(_ any) // ERROR "undefined"
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