go/types: comp literals to accept type sets with single underlying types

This is a clean port of CL 357915 to go/types.

Change-Id: Idf5850a8bdcf3596c561c97bcd60539945139743
Reviewed-on: https://go-review.googlesource.com/c/go/+/359877
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

diff --git a/src/go/types/expr.go b/src/go/types/expr.go
index 3a09dfd85f9b72cc0550c0502f5abeea3054c253..8b26e64971f5d3d3af33242efcd12a580ad8b2d9 100644 (file)
--- a/src/go/types/expr.go
+++ b/src/go/types/expr.go
@@ -1223,7 +1223,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
                        goto Error
                }
 
-               switch utyp := optype(base).(type) {
+               switch utyp := singleUnder(base).(type) {
                case *Struct:
                        if len(e.Elts) == 0 {
                                break

diff --git a/src/go/types/testdata/check/compliterals.go2 b/src/go/types/testdata/check/compliterals.go2
new file mode 100644 (file)
index 0000000..60eac97
--- /dev/null
+++ b/src/go/types/testdata/check/compliterals.go2
@@ -0,0 +1,22 @@
+// Copyright 2012 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.
+
+// Composite literals with parameterized types
+
+package comp_literals
+
+type myStruct struct {
+       f int
+}
+
+type slice[E any] []E
+
+func struct_literals[S struct{f int}|myStruct]() {
+       _ = S{}
+       _ = S{0}
+       _ = S{f: 0}
+
+        _ = slice[int]{1, 2, 3}
+        _ = slice[S]{{}, {0}, {f:0}}
+}