{0, 12, true},
		{math.MinInt64, 12, true},
	}

	for _, v := range vectors {
		ok := fitsInBase256(v.width, v.in)
		if ok != v.ok {
			t.Errorf("fitsInBase256(%d, %d): got %v, want %v", v.in, v.width, ok, v.ok)
		}
	}
}

func TestParseNumeric(t *testing.T) {
	vectors := []struct {
		in   string
		want int64
		ok   bool
	}{
		// Test base-256 (binary) encoded values.
		{"", 0, true},
		{"\x80", 0, true},

			if decl.Recv != nil && len(decl.Recv.List) > 0 {
				recvType := decl.Recv.List[0].Type
				if recvType != nil {
					t := recvType
					if star, ok := unparen(t).(*ast.StarExpr); ok {
						t = star.X
					}
					if sel, ok := unparen(t).(*ast.SelectorExpr); ok {
						var buf strings.Builder
						format.Node(&buf, fset, recvType)
						error_(sel.Pos(), `cannot define new methods on non-local type %s`, &buf)
					}

			ok:       false,
			out:      "+A\n+C\n+E\n+F\n",
		},
		{
			name:     "feature removed",
			features: []string{"C", "A"},
			required: []string{"A", "B", "C"},
			ok:       false,
			out:      "-B\n",
		},
		{
			name:      "exception removal",
			features:  []string{"A", "C"},
			required:  []string{"A", "B", "C"},
			exception: []string{"B"},
			ok:        true,

			// We are starting so many processes that on
			// some systems (problem seen on Darwin,
			// Dragonfly, OpenBSD) the fork call will fail
			// with EAGAIN.
			if pe, ok := err.(*os.PathError); ok {
				err = pe.Err
			}
			if se, ok := err.(syscall.Errno); ok && (se == syscall.EAGAIN || se == syscall.EMFILE) {
				time.Sleep(time.Millisecond)
				continue
			}

			t.Error(err)
			return
		}

reserved.
L2::: Use of this source code is governed by a BSD-style
L3::: license that can be found in the LICENSE file.
L4:
L5:@echo off
L6:
L7:setlocal
L8:
L9:if exist make.bat goto ok
L10:echo all.bat must be run from go\src
L11::: cannot exit: would kill parent command interpreter
L12:goto end
L13::ok
L14:
L15:call .\make.bat --no-banner --no-local
L16:if %GOBUILDFAIL%==1 goto end
L17:call .\run.bat --no-rebuild --no-local
L18:if %GOBUILDFAIL%==1 goto end
L19:"%GOTOOLDIR%/dist" banner
...

		fatal("usage: callback testname")
	}
	switch os.Args[1] {
	default:
		fatal("unknown test %q", os.Args[1])
	case "Call":
		testCall()
	case "Callback":
		testCallback()
	}
	println("OK")
}

func fatal(f string, args ...any) {
	fmt.Fprintln(os.Stderr, fmt.Sprintf(f, args...))
	os.Exit(1)
}

type GoCallback struct{}

func (p *GoCallback) Run() string {
	return "GoCallback.Run"
}

//
// For unexpected panics, calls t.Fatal.
func tryParse(t *testing.T, parse func()) (err error) {
	panicOnError = true
	defer func() {
		panicOnError = false

		e := recover()
		var ok bool
		if err, ok = e.(error); e != nil && !ok {
			t.Fatal(e)
		}
	}()

	parse()

	return nil
}

func testBadOperandParser(t *testing.T, parser *Parser, tests []badOperandTest) {
	for _, test := range tests {

		cmd.Env = append(cmd.Environ(),
			"CGO_CFLAGS="+cflags,
			"CGO_CXXFLAGS="+cflags,
			"CGO_LDFLAGS="+cflags)
	}
	out, err := cmd.CombinedOutput()
	if string(out) != "OK\n" {
		t.Errorf("%s", string(out))
	}
	if err != nil {
		t.Errorf("%s", err)
	}
}

func mustHaveCxx(t *testing.T) {
	// Ask the go tool for the CXX it's configured to use.

</p>

<pre>
v, ok = x.(T)
v, ok := x.(T)
var v, ok = x.(T)
var v, ok interface{} = x.(T) // dynamic types of v and ok are T and bool
</pre>

<p>
yields an additional untyped boolean value. The value of <code>ok</code> is <code>true</code>
if the assertion holds. Otherwise it is <code>false</code> and the value of <code>v</code> is

func BenchmarkReaderWriteToOptimal(b *testing.B) {
	const bufSize = 16 << 10
	buf := make([]byte, bufSize)
	r := bytes.NewReader(buf)
	srcReader := NewReaderSize(onlyReader{r}, 1<<10)
	if _, ok := io.Discard.(io.ReaderFrom); !ok {
		b.Fatal("io.Discard doesn't support ReaderFrom")
	}
	for i := 0; i < b.N; i++ {
		r.Seek(0, io.SeekStart)
		srcReader.Reset(onlyReader{r})
		n, err := srcReader.WriteTo(io.Discard)