func (info *Info) recordTypes() bool {
	return info.Types != nil || info.StoreTypesInSyntax
}

// TypeOf returns the type of expression e, or nil if not found.
// Precondition 1: the Types map is populated or StoreTypesInSyntax is set.
// Precondition 2: Uses and Defs maps are populated.
func (info *Info) TypeOf(e syntax.Expr) Type {
	if info.Types != nil {
		if t, ok := info.Types[e]; ok {
			return t.Type
		}

// Copyright 2013 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.

package types2

import (
	"cmd/compile/internal/syntax"
	. "internal/types/errors"
)

// labels checks correct label use in body.
func (check *Checker) labels(body *syntax.BlockStmt) {
	// set of all labels in this body
	all := NewScope(nil, body.Pos(), syntax.EndPos(body), "label")

var (
	universeIota       Object
	universeByte       Type // uint8 alias, but has name "byte"
	universeRune       Type // int32 alias, but has name "rune"
	universeAnyNoAlias *TypeName
	universeAnyAlias   *TypeName
	universeError      Type
	universeComparable Object
)

// Typ contains the predeclared *Basic types indexed by their
// corresponding BasicKind.
//
// The *Basic type for Typ[Byte] will have the name "uint8".

var (
	universeIota       Object
	universeByte       Type // uint8 alias, but has name "byte"
	universeRune       Type // int32 alias, but has name "rune"
	universeAnyNoAlias *TypeName
	universeAnyAlias   *TypeName
	universeError      Type
	universeComparable Object
)

// Typ contains the predeclared *Basic types indexed by their
// corresponding BasicKind.
//
// The *Basic type for Typ[Byte] will have the name "uint8".

	// "V and T have identical underlying types if tags are ignored
	// and V and T are not type parameters"
	if IdenticalIgnoreTags(Vu, Tu) && Vp == nil && Tp == nil {
		return true
	}

	// "V and T are unnamed pointer types and their pointer base types
	// have identical underlying types if tags are ignored
	// and their pointer base types are not type parameters"
	if V, ok := V.(*Pointer); ok {

	_ = uint16(16) << s
	_ = uint32(32 << s)
	_ = uint64(64 << s + s)
	_ = (interface{})("foo")
	_ = (interface{})(nil)
)`
	types := make(map[syntax.Expr]TypeAndValue)
	mustTypecheck(src, nil, &Info{Types: types})

	for x, tv := range types {
		var want Type
		switch x := x.(type) {
		case *syntax.BasicLit:
			switch x.Value {
			case `8`:
				want = Typ[Uint8]
			case `16`:
				want = Typ[Uint16]

	// "V and T have identical underlying types if tags are ignored
	// and V and T are not type parameters"
	if IdenticalIgnoreTags(Vu, Tu) && Vp == nil && Tp == nil {
		return true
	}

	// "V and T are unnamed pointer types and their pointer base types
	// have identical underlying types if tags are ignored
	// and their pointer base types are not type parameters"
	if V, ok := V.(*Pointer); ok {

// implied by the methods and the type set described by the terms and the
// comparable bit. To test whether a type is included in a type set
// ("implements" relation), the type must implement all methods _and_ be
// an element of the type set described by the terms and the comparable bit.
// If the term list describes the set of all types and comparable is true,

// If the term list describes the set of all types and comparable is true,
// only comparable types are meant; in all other cases comparable is false.
type _TypeSet struct {
	methods    []*Func  // all methods of the interface; sorted by unique ID
	terms      termlist // type terms of the type set
	comparable bool     // invariant: !comparable || terms.isAll()
}

// IsEmpty reports whether type set s is the empty set.

//  - We say that a Named type is "instantiated" if it has been constructed by
//    instantiating a generic named type with type arguments.
//  - We say that a Named type is "declared" if it corresponds to a type
//    declaration in the source. Instantiated named types correspond to a type
//    instantiation in the source, not a declaration. But their Origin type is
//    a declared type.