type of a specially annotated switch expression.
The switch expression is evaluated exactly once in a switch statement.
</p>

<h4 id="Expression_switches">Expression switches</h4>

<p>
In an expression switch,
the switch expression is evaluated and
the case expressions, which need not be constants,
are evaluated left-to-right and top-to-bottom; the first one that equals the
switch expression

	// literal to evaluate the arguments at the right time.
	//    defer func() func() {
	//            _cgo0 := p
	//            return func() {
	//                    _cgoCheckPointer(_cgo0, nil)
	//                    C.f(_cgo0)
	//            }
	//    }()()
	// This works because the defer statement evaluates the first
	// function literal in order to get the function to call.

type of a specially annotated switch expression.
The switch expression is evaluated exactly once in a switch statement.
</p>

<h4 id="Expression_switches">Expression switches</h4>

<p>
In an expression switch,
the switch expression is evaluated and
the case expressions, which need not be constants,
are evaluated left-to-right and top-to-bottom; the first one that equals the
switch expression

	for i, test := range exprTests {
		p.start(lex.Tokenize(test.input))
		result := int64(p.expr())
		if result != test.output {
			t.Errorf("%d: %q evaluated to %d; expected %d", i, test.input, result, test.output)
		}
		tok := p.next()
		if test.atEOF && tok.ScanToken != scanner.EOF {
			t.Errorf("%d: %q: at EOF got %s", i, test.input, tok)

always have [`os.ModeIrregular`](/pkg/os#ModeIrregular) set. As a result of these changes,
[`filepath.EvalSymlinks`](/pkg/path/filepath#EvalSymlinks) no longer evaluates
mount points, which was a source of many inconsistencies and bugs.
At previous versions (`winsymlink=0`), mount points are treated as symlinks,
and other reparse points with non-default [`os.ModeType`](/pkg/os#ModeType) bits

precedence, not the C-like precedence of the original.
Thus <code>3&amp;1&lt;&lt;2</code> is 4, not 0—it parses as <code>(3&amp;1)&lt;&lt;2</code>
not <code>3&amp;(1&lt;&lt;2)</code>.
Also, constants are always evaluated as 64-bit unsigned integers.
Thus <code>-2</code> is not the integer value minus two,
but the unsigned 64-bit integer with the same bit pattern.
The distinction rarely matters but

On Windows, [EvalSymlinks] no longer evaluates mount points,
which was a source of many inconsistencies and bugs.
This behavior is controlled by the `winsymlink` setting.
For Go 1.23, it defaults to `winsymlink=1`.
Previous versions default to `winsymlink=0`.

On Windows, [EvalSymlinks] no longer tries to normalize
volumes to drive letters, which was not always even possible.
This behavior is controlled by the `winreadlinkvolume` setting.

		return false
	}
	if !offsetOk && addr.Offset != 0 {
		p.errorf("%s symbol %q must not be offset from SB", pseudo, symbolName(addr))
		return false
	}
	return true
}

// evalInteger evaluates an integer constant for a pseudo-op.
func (p *Parser) evalInteger(pseudo string, operands []lex.Token) int64 {
	addr := p.address(operands)
	return p.getConstantPseudo(pseudo, &addr)
}