go/test/typeparam/issue39755.go

// compile

// 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.

// copied from cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go

package p

func _[T interface{ ~map[string]int }](x T) {
	_ = x == nil
}

// simplified test case from issue

type PathParamsConstraint interface {
	~map[string]string | ~[]struct{ key, value string }
}

type PathParams[T PathParamsConstraint] struct {
	t T
}

func (pp *PathParams[T]) IsNil() bool {
	return pp.t == nil // this must succeed
}