These new behaviors are only enabled when the main Go program
is in a module with a `go.mod` `go` line using Go 1.23.0 or later.
When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)
can be used to revert back to asynchronous channel behaviors

// license that can be found in the LICENSE file.

package tls

import (
	"internal/godebug"
	"slices"
	_ "unsafe" // for linkname
)

// Defaults are collected in this file to allow distributions to more easily patch
// them to apply local policies.

var tlskyber = godebug.New("tlskyber")

func defaultCurvePreferences() []CurveID {
	if tlskyber.Value() == "0" {

//
// This function is expensive! Call it sparingly.
func Enabled() bool {
	// The only reliable way to compute the answer is to invoke go/types.
	// We don't parse the GODEBUG environment variable, because
	// (a) it's tricky to do so in a manner that is consistent
	//     with the godebug package; in particular, a simple
	//     substring check is not good enough. The value is a
	//     rightmost-wins list of options. But more importantly:

	*p = newIncNonDefault
	godebugNewIncNonDefault.Store(p)
}

// A godebugInc provides access to internal/godebug's IncNonDefault function
// for a given GODEBUG setting.
// Calls before internal/godebug registers itself are dropped on the floor.
type godebugInc struct {
	name string
	inc  atomic.Pointer[func()]
}

func (g *godebugInc) IncNonDefault() {
	inc := g.inc.Load()
	if inc == nil {

3DES cipher suites were removed from the default list used when
[Config.CipherSuites] is nil. The default can be reverted adding `tls3des=1` to

For inbound requests, the new [Request.Pattern] field contains the [ServeMux]
pattern (if any) that matched the request. This field is not set when

<!-- CL 577715, CL 579076 -->
By default, go/types now produces [Alias] type nodes for type aliases.
This behavior can be controlled by the `GODEBUG` `gotypesalias` flag.

				continue field
			}
		}

		print("GODEBUG sys/cpu: unknown cpu feature \"", key, "\"\n")
	}

	for _, o := range options {
		if !o.Specified {
			continue
		}

		if o.Enable && !*o.Feature {
			print("GODEBUG sys/cpu: can not enable \"", o.Name, "\", missing CPU support\n")
			continue
		}

		if !o.Enable && o.Required {

// compile -godebug gotypesalias=1

// Copyright 2024 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package p

type A = int

type T[P any] *A

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package aliasTypes

type _ = int