// upper case, giving priority to the special casing rules.
func ToUpperSpecial(c unicode.SpecialCase, s []byte) []byte {
	return Map(c.ToUpper, s)
}

// ToLowerSpecial treats s as UTF-8-encoded bytes and returns a copy with all the Unicode letters mapped to their
// lower case, giving priority to the special casing rules.
func ToLowerSpecial(c unicode.SpecialCase, s []byte) []byte {
	return Map(c.ToLower, s)

// much practical consequence because the expressions we
// see in assembly code are simple, but for the record:
//
// 1) Evaluation uses uint64; the old one used int64.
// 2) Precedence uses Go rules not C rules.

// expr = term | term ('+' | '-' | '|' | '^') term.
func (p *Parser) expr() uint64 {
	value := p.term()
	for {
		switch p.peek() {
		case '+':
			p.next()
			value += p.term()

	buf := NewBuffer(make([]byte, n))
	for i := 0; i < b.N; i++ {
		buf.Reset()
		for i := 0; i < n; i++ {
			buf.WriteByte('x')
		}
	}
}

func BenchmarkWriteRune(b *testing.B) {
	const n = 4 << 10
	const r = '☺'
	b.SetBytes(int64(n * utf8.RuneLen(r)))
	buf := NewBuffer(make([]byte, n*utf8.UTFMax))
	for i := 0; i < b.N; i++ {
		buf.Reset()
		for i := 0; i < n; i++ {
			buf.WriteRune(r)
		}
	}
}

called by C code may take a Go pointer but it must preserve the property
that the Go memory to which it points (and the Go memory to which that
memory points, and so on) is pinned.

These rules are checked dynamically at runtime. The checking is
controlled by the cgocheck setting of the GODEBUG environment
variable. The default setting is GODEBUG=cgocheck=1, which implements

				tw.WriteHeader(file.hdr)
				tw.Write(file.body)
			}
			tw.Close()
			b.Run(v.label, func(b *testing.B) {
				b.ReportAllocs()
				// Read from the byte buffer.
				for i := 0; i < b.N; i++ {
					r.Reset(buf.Bytes())
					tr := NewReader(&r)
					if _, err := tr.Next(); err != nil {
						b.Errorf("unexpected Next error: %v", err)
					}
					if _, err := io.Copy(io.Discard, tr); err != nil {