Also for security reasons, only a limited set of characters are
permitted, notably alphanumeric characters and a few symbols, such as
'.', that will not be interpreted in unexpected ways. Attempts to use
forbidden characters will get a "malformed #cgo argument" error.

When building, the CGO_CFLAGS, CGO_CPPFLAGS, CGO_CXXFLAGS, CGO_FFLAGS and
CGO_LDFLAGS environment variables are added to the flags derived from

		0xff, 0xff, 0xff, 0x20, 0x00,
	}
	defer func() {
		if r := recover(); r != nil {
			t.Fatalf("NewReader panicked: %s", r)
		}
	}()
	// Previously, this would trigger a panic as we attempt to read from
	// an io.SectionReader which would access a slice at a negative offset
	// as the section reader offset & size were < 0.
	NewReader(bytes.NewReader(data), int64(len(data))+1875)

indirection <code>*x</code> denotes the <a href="#Variables">variable</a> of type <code>T</code> pointed
to by <code>x</code>.
If <code>x</code> is <code>nil</code>, an attempt to evaluate <code>*x</code>
will cause a <a href="#Run_time_panics">run-time panic</a>.
</p>

<pre>
&amp;x
&amp;a[f(2)]
&amp;Point{2, 3}
*p
*pf(x)

var x *int = nil

type is a <a href="#Type_parameter_declarations">type parameter</a> with an empty
<a href="#Interface_types">type set</a>. Functions with such type parameters
cannot be <a href="#Instantiations">instantiated</a>; any attempt will lead
to an error at the instantiation site.
</p>

<h3 id="Qualified_identifiers">Qualified identifiers</h3>

<p>
A <i>qualified identifier</i> is an identifier qualified with a package name prefix.

func (w *Walker) pushScope(name string) (popFunc func()) {
	w.scope = append(w.scope, name)
	return func() {
		if len(w.scope) == 0 {
			log.Fatalf("attempt to leave scope %q with empty scope list", name)
		}
		if w.scope[len(w.scope)-1] != name {
			log.Fatalf("attempt to leave scope %q, but scope is currently %#v", name, w.scope)
		}
		w.scope = w.scope[:len(w.scope)-1]
	}
}

}
</pre>

<p>
it can happen that <code>g</code> prints <code>2</code> and then <code>0</code>.
</p>

<p>
This fact invalidates a few common idioms.
</p>

<p>
Double-checked locking is an attempt to avoid the overhead of synchronization.
For example, the <code>twoprint</code> program might be
incorrectly written as:
</p>

<pre>
var a string
var done bool

func setup() {

			t.Errorf("splitUSTARPath(%q):\ngot  (%q, %q, %v)\nwant (%q, %q, %v)",
				v.input, prefix, suffix, ok, v.prefix, v.suffix, v.ok)
		}
	}
}

// TestIssue12594 tests that the Writer does not attempt to populate the prefix
// field when encoding a header in the GNU format. The prefix field is valid
// in USTAR and PAX, but not GNU.
func TestIssue12594(t *testing.T) {
	names := []string{