and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

The runtime/cgo.Handle type can be used to safely pass Go values
between Go and C. See the runtime/cgo package documentation for details.

Note: the current implementation has a bug. While Go code is permitted

pkg unique, func Make[$0 comparable]($0) Handle[$0] #62483
pkg unique, method (Handle[$0]) Value() $0 #62483

// ending offset is aligned down to the nearest block edge.
//
// Even though the Go tar Reader and the BSD tar utility can handle entries
// with arbitrary offsets and lengths, the GNU tar utility can only handle
// offsets and lengths that are multiples of blockSize.
func alignSparseEntries(src []sparseEntry, size int64) []sparseEntry {
	dst := src[:0]
	for _, s := range src {

`Make[T]` function, which produces a reference to a canonical copy of
the value in the form of a `Handle[T]`.
Two `Handle[T]` are equal if and only if the values used to produce the
handles are equal, allowing programs to deduplicate values and reduce
their memory footprint.
Comparing two `Handle[T]` values is efficient, reducing down to a simple

		}
		if asciiSpace[c] == 0 {
			break
		}
	}

	// At this point s[start:stop] starts and ends with an ASCII
	// non-space bytes, so we're done. Non-ASCII cases have already
	// been handled above.
	if start == stop {
		// Special case to preserve previous TrimLeftFunc behavior,
		// returning nil instead of empty slice if all spaces.
		return nil
	}
	return s[start:stop]
}

	// ARM only.
	if !p.arch.InFamily(sys.ARM, sys.ARM64) {
		return false
	}
	// R1<<...
	if lex.IsRegisterShift(p.peek()) {
		return true
	}
	// R(1)<<...   Ugly check. TODO: Rethink how we handle ARM register shifts to be
	// less special.
	if p.peek() != '(' || len(p.input)-p.inputPos < 4 {
		return false
	}
	return p.at('(', scanner.Int, ')') && lex.IsRegisterShift(p.input[p.inputPos+3].ScanToken)
}

pkg math/rand/v2, type Source interface, Uint64() uint64 #61716
pkg math/rand/v2, type Zipf struct #61716
pkg net, method (*TCPConn) WriteTo(io.Writer) (int64, error) #58808
pkg net/http, func FileServerFS(fs.FS) Handler #51971
pkg net/http, func NewFileTransportFS(fs.FS) RoundTripper #51971
pkg net/http, func ServeFileFS(ResponseWriter, *Request, fs.FS, string) #51971
pkg net/http, method (*Request) PathValue(string) string #61410

			case TypeGNULongLink:
				gnuLongLink = p.parseString(realname)
			}
			continue // This is a meta header affecting the next header
		default:
			// The old GNU sparse format is handled here since it is technically
			// just a regular file with additional attributes.

			if err := mergePAX(hdr, paxHdrs); err != nil {
				return nil, err
			}
			if gnuLongName != "" {

	// flags.
	if h.raw && !h.hasDataDescriptor() {
		b.uint32(h.CRC32)
		b.uint32(uint32(min(h.CompressedSize64, uint32max)))
		b.uint32(uint32(min(h.UncompressedSize64, uint32max)))
	} else {
		// When this package handle the compression, these values are
		// always written to the trailing data descriptor.
		b.uint32(0) // crc32
		b.uint32(0) // compressed size
		b.uint32(0) // uncompressed size
	}
	b.uint16(uint16(len(h.Name)))

		name = buf.String()
	}
	switch typ := typ.Underlying().(type) {
	case *types.Struct:
		w.emitStructType(name, typ)
	case *types.Interface:
		w.emitIfaceType(name, typ)
		return // methods are handled by emitIfaceType
	default:
		w.emitf("type %s %s", name, w.typeString(typ.Underlying()))
	}

	// emit methods with value receiver
	var methodNames map[string]bool
	vset := types.NewMethodSet(typ)