1// errorcheck -G
2
3// Copyright 2020 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Basic type parameter list type-checking (not syntax) errors.
8
9package tparam1
10
11// The predeclared identifier "any" may be used in place of interface{}.
12var _ any
13
14func _(_ any)
15
16type _[_ any] struct{}
17
18const N = 10
19
20type (
21	_                     []struct{}  // slice
22	_                     [N]struct{} // array
23	_[T any]              struct{}
24	_[T, T any]           struct{} // ERROR "T redeclared"
25	_[T1, T2 any, T3 any] struct{}
26)
27
28func _[T any]()             {}
29func _[T, T any]()          {} // ERROR "T redeclared"
30func _[T1, T2 any](x T1) T2 { panic(0) }
31
32// Type parameters are visible from opening [ to end of function.
33type C interface{}
34
35func _[T interface{}]()        {}
36func _[T C]()                  {}
37func _[T struct{}]()           {} // ok if #48424 is accepted
38func _[T interface{ m() T }]() {}
39func _[T1 interface{ m() T2 }, T2 interface{ m() T1 }]() {
40	var _ T1
41}
42
43// TODO(gri) expand this
44