struct_, union_, or enum_, as in C.struct_stat.

The size of any C type T is available as C.sizeof_T, as in
C.sizeof_struct_stat.

A C function may be declared in the Go file with a parameter type of
the special name _GoString_. This function may be called with an
ordinary Go string value. The string length, and a pointer to the
string contents, may be accessed by calling the C functions

	size_t _GoStringLen(_GoString_ s);

		// if modification time is the only timestamp being encoded.
		var mbuf [9]byte // 2*SizeOf(uint16) + SizeOf(uint8) + SizeOf(uint32)
		mt := uint32(fh.Modified.Unix())
		eb := writeBuf(mbuf[:])
		eb.uint16(extTimeExtraID)
		eb.uint16(5)  // Size: SizeOf(uint8) + SizeOf(uint32)
		eb.uint8(1)   // Flags: ModTime
		eb.uint32(mt) // ModTime
		fh.Extra = append(fh.Extra, mbuf[:]...)
	}

//     pthread_mutex_lock(&mu);
//     done = all_done;
//     pthread_mutex_unlock(&mu);
//   }
//   return NULL;
// }
//
// void trial(int argc) {
//   int i;
//   nts = argc;
//   t = calloc(nts, sizeof(pthread_t));
//   pthread_mutex_init(&mu, NULL);
//   for (i = 0; i < nts; i++) {
//     pthread_create(&t[i], NULL, aFn, NULL);
//   }
// }
//
// void cleanup(void) {
//   int i;
//   pthread_mutex_lock(&mu);

	// the compiler is going to pad it by one (see issue 9401).
	// We can't permit that, because then the size of the Go
	// struct will not be the same as the size of the C struct.
	// Our only option in such a case is to remove the field,
	// which means that it cannot be referenced from Go.
	for off > 0 && sizes[len(sizes)-1] == 0 {
		n := len(sizes)
		fld = fld[0 : n-1]
		sizes = sizes[0 : n-1]

a <a href="#Run_time_panics">run-time panic</a> occurs.
</p>

<h3 id="Size_and_alignment_guarantees">Size and alignment guarantees</h3>

<p>
For the <a href="#Numeric_types">numeric types</a>, the following sizes are guaranteed:
</p>

<pre class="grammar">
type                                 size in bytes

byte, uint8, int8                     1
uint16, int16                         2

	var buf Buffer
	n := 0
	for r := rune(0); r < NRune; r++ {
		size := utf8.EncodeRune(b[n:], r)
		nbytes, err := buf.WriteRune(r)
		if err != nil {
			t.Fatalf("WriteRune(%U) error: %s", r, err)
		}
		if nbytes != size {
			t.Fatalf("WriteRune(%U) expected %d, got %d", r, size, nbytes)
		}
		n += size
	}
	b = b[0:n]

	// Check the resulting bytes
	if !Equal(buf.Bytes(), b) {

		t.Errorf("%v", err)
		return
	}

	// For very large files, just check that the size is correct.
	// The content is expected to be all zeros.
	// Don't bother uncompressing: too big.
	if ft.Content == nil && ft.File == "" && ft.Size > 0 {
		if size != ft.Size {
			t.Errorf("%v: uncompressed size %#x, want %#x", ft.Name, size, ft.Size)
		}
		r.Close()
		return
	}

	var b bytes.Buffer

		{"DATA", "0", "expect two operands for DATA"},
		{"DATA", "(0), 1", "expect /size for DATA argument"},
		{"DATA", "@B(SB)/4,0", "expected '(', found B"}, // Issue 23580.
		{"DATA", "·A(SB)/4,0", "DATA value must be an immediate constant or address"},
		{"DATA", "·B(SB)/4,$0", ""},
		{"DATA", "·C(SB)/5,$0", "bad int size for DATA argument: 5"},
		{"DATA", "·D(SB)/5,$0.0", "bad float size for DATA argument: 5"},

</pre>

<p>
A (variable of) type <code>T</code> has <i>variable size</i> if <code>T</code>
is a <a href="#Type_parameter_declarations">type parameter</a>, or if it is an
array or struct type containing elements
or fields of variable size. Otherwise the size is <i>constant</i>.
Calls to <code>Alignof</code>, <code>Offsetof</code>, and <code>Sizeof</code>
are compile-time <a href="#Constant_expressions">constant expressions</a> of

		}
		if v, ok := h.PAXRecords[paxKey]; ok && v == s {
			paxHdrs[paxKey] = v
		}
	}
	verifyNumeric := func(n int64, size int, name, paxKey string) {
		if !fitsInBase256(size, n) {
			whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%d", name, n)
			format.mustNotBe(FormatGNU)
		}
		if !fitsInOctal(size, n) {
			whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%d", name, n)
			format.mustNotBe(FormatUSTAR)