// identical element types), the single underlying type is the restricted
// channel type if the restrictions are always the same, or nil otherwise.
func coreType(t Type) Type {
	t = Unalias(t)
	tpar, _ := t.(*TypeParam)
	if tpar == nil {
		return under(t)
	}

	var su Type
	if tpar.underIs(func(u Type) bool {
		if u == nil {
			return false
		}
		if su != nil {
			u = match(su, u)
			if u == nil {

// NormalTerms returns a slice of terms representing the normalized structural
// type restrictions of a type, if any.
//
// For all types other than *types.TypeParam, *types.Interface, and
// *types.Union, this is just a single term with Tilde() == false and
// Type() == typ. For *types.TypeParam, *types.Interface, and *types.Union, see
// below.
//
// Structural type restrictions of a type parameter are created via

// identical element types), the single underlying type is the restricted
// channel type if the restrictions are always the same, or nil otherwise.
func coreType(t Type) Type {
	t = Unalias(t)
	tpar, _ := t.(*TypeParam)
	if tpar == nil {
		return under(t)
	}

	var su Type
	if tpar.underIs(func(u Type) bool {
		if u == nil {
			return false
		}
		if su != nil {
			u = match(su, u)
			if u == nil {

package types

// A Type represents a type of Go.
// All types implement the Type interface.
type Type interface {
	// Underlying returns the underlying type of a type.
	// Underlying types are never Named, TypeParam, or Alias types.
	//
	// See https://go.dev/ref/spec#Underlying_types.
	Underlying() Type

	// String returns a string representation of a type.
	String() string

//
// Do not remove or change the type signature.
// See go.dev/issue/67401.
//
//go:linkname badlinkname_Checker_infer go/types.(*Checker).infer

				if p.Value == "_" {
					if check.recvTParamMap == nil {
						check.recvTParamMap = make(map[*syntax.Name]*TypeParam)
					}
					check.recvTParamMap[p] = tparams[i]
				}
			}
			// determine receiver type to get its type parameters
			// and the respective type parameter bounds
			var recvTParams []*TypeParam
			if rname != nil {
				// recv should be a Named type (otherwise an error is reported elsewhere)

	switch Unalias(t).(type) {
	case *Basic, *Named, *TypeParam:
		return true
	}
	return false
}

// isTypeLit reports whether t is a type literal.
// This includes all non-defined types, but also basic types.
// isTypeLit may be called with types that are not fully set up.
func isTypeLit(t Type) bool {
	switch Unalias(t).(type) {
	case *Named, *TypeParam:
		return false
	}
	return true
}

	switch Unalias(t).(type) {
	case *Basic, *Named, *TypeParam:
		return true
	}
	return false
}

// isTypeLit reports whether t is a type literal.
// This includes all non-defined types, but also basic types.
// isTypeLit may be called with types that are not fully set up.
func isTypeLit(t Type) bool {
	switch Unalias(t).(type) {
	case *Named, *TypeParam:
		return false
	}
	return true
}

		name += " (" + strings.Join(parentheticals, ", ") + ")"
	}

	return name
}

func typeName(t types.Type) string {
	type hasTypeName interface{ Obj() *types.TypeName } // Alias, Named, TypeParam
	switch t := t.(type) {
	case *types.Basic:
		return t.Name()
	case hasTypeName:
		return t.Obj().Name()
	}
	return ""
}

func run(pass *analysis.Pass) (interface{}, error) {

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)

	// x's type is identical to T
	if Identical(V, T) {
		return true, 0
	}

	Vu := under(V)
	Tu := under(T)
	Vp, _ := V.(*TypeParam)
	Tp, _ := T.(*TypeParam)

	// x is an untyped value representable by a value of type T.
	if isUntyped(Vu) {
		assert(Vp == nil)
		if Tp != nil {
			// T is a type parameter: x is assignable to T if it is