[`jstmpllitinterp` setting](/pkg/html/template#hdr-Security_Model).
This behavior was backported to Go 1.19.8+ and Go 1.20.3+.

Go 1.21 introduced a limit on the maximum number of MIME headers and multipart
forms, controlled by the
[`multipartmaxheaders` and `multipartmaxparts` settings](/pkg/mime/multipart#hdr-Limits)
respectively.
This behavior was backported to Go 1.19.8+ and Go 1.20.3+.

hex_float_lit     = "0" ( "x" | "X" ) hex_mantissa hex_exponent .
hex_mantissa      = [ "_" ] hex_digits "." [ hex_digits ] |
                    [ "_" ] hex_digits |
                    "." hex_digits .
hex_exponent      = ( "p" | "P" ) [ "+" | "-" ] decimal_digits .
</pre>

<pre>
0.
72.40
072.40       // == 72.40
2.71828
1.e+0
6.67428e-11
1E6
.25
.12345E+5

			t.Errorf("ReadByte: got (%q, %v), want (%q, %v)", c, err, byte(0), io.EOF)
		}
	}
}

func TestLargeStringWrites(t *testing.T) {
	var buf Buffer
	limit := 30
	if testing.Short() {
		limit = 9
	}
	for i := 3; i < limit; i += 3 {
		s := fillString(t, "TestLargeWrites (1)", &buf, "", 5, testString)
		empty(t, "TestLargeStringWrites (2)", &buf, s, make([]byte, len(testString)/i))
	}

For example:

	// #cgo pkg-config: png cairo
	// #include <png.h>
	import "C"

The default pkg-config tool may be changed by setting the PKG_CONFIG environment variable.

For security reasons, only a limited set of flags are allowed, notably -D, -U, -I, and -l.
To allow additional flags, set CGO_CFLAGS_ALLOW to a regular expression
matching the new flags. To disallow flags that would otherwise be allowed,

hex_float_lit     = "0" ( "x" | "X" ) hex_mantissa hex_exponent .
hex_mantissa      = [ "_" ] hex_digits "." [ hex_digits ] |
                    [ "_" ] hex_digits |
                    "." hex_digits .
hex_exponent      = ( "p" | "P" ) [ "+" | "-" ] decimal_digits .
</pre>

<pre>
0.
72.40
072.40       // == 72.40
2.71828
1.e+0
6.67428e-11
1E6
.25
.12345E+5

	// larger chunks as the source of the write, as when the source
	// is too large we are basically just thrashing the CPU D-cache.
	// So if the result length is larger than an empirically-found
	// limit (8KB), we stop growing the source string once the limit
	// is reached and keep reusing the same source string - that
	// should therefore be always resident in the L1 cache - until we
	// have completed the construction of the result.

goroutines coordinate using the <code>limit</code> channel to ensure
that at most three are running work functions at a time.
</p>

<pre>
var limit = make(chan int, 3)

func main() {
	for _, w := range work {
		go func(w func()) {
			limit &lt;- 1
			w()
			&lt;-limit
		}(w)
	}
	select{}
}
</pre>

<h3 id="locks">Locks</h3>

func TestRoundTrip(t *testing.T) {
	data := []byte("some file contents")

	var b bytes.Buffer
	tw := NewWriter(&b)
	hdr := &Header{
		Name:       "file.txt",
		Uid:        1 << 21, // Too big for 8 octal digits
		Size:       int64(len(data)),
		ModTime:    time.Now().Round(time.Second),
		PAXRecords: map[string]string{"uid": "2097152"},
		Format:     FormatPAX,
		Typeflag:   TypeReg,
	}