"hash"
	"testing"
)

func TestUnseededHash(t *testing.T) {
	m := map[uint64]struct{}{}
	for i := 0; i < 1000; i++ {
		h := new(Hash)
		m[h.Sum64()] = struct{}{}
	}
	if len(m) < 900 {
		t.Errorf("empty hash not sufficiently random: got %d, want 1000", len(m))
	}
}

func TestSeededHash(t *testing.T) {
	s := MakeSeed()
	m := map[uint64]struct{}{}
	for i := 0; i < 1000; i++ {
		h := new(Hash)
		h.SetSeed(s)

		use121 = true
		httpmuxgo121.IncNonDefault()
	}
}

// serveMux121 holds the state of a ServeMux needed for Go 1.21 behavior.
type serveMux121 struct {
	mu    sync.RWMutex
	m     map[string]muxEntry
	es    []muxEntry // slice of entries sorted from longest to shortest.
	hosts bool       // whether any patterns contain hostnames
}

type muxEntry struct {
	h       Handler
	pattern string
}

package noder

import (
	"cmd/compile/internal/base"
	"cmd/compile/internal/syntax"
	"cmd/internal/src"
)

// A posMap handles mapping from syntax.Pos to src.XPos.
type posMap struct {
	bases map[*syntax.PosBase]*src.PosBase
	cache struct {
		last *syntax.PosBase
		base *src.PosBase
	}
}

type poser interface{ Pos() syntax.Pos }
type ender interface{ End() syntax.Pos }

func NewInheritanceMatcher(t []language.Tag) *InheritanceMatcher {
	tags := &InheritanceMatcher{make(map[language.Tag]int)}
	for i, tag := range t {
		ct, err := language.All.Canonicalize(tag)
		if err != nil {
			ct = tag
		}
		tags.index[ct] = i
	}
	return tags
}

type InheritanceMatcher struct {
	index map[language.Tag]int
}

					entries = append(entries, entry[string, any]{c, nil})
				}
				b.ResetTimer()
				for i := 0; i < b.N; i++ {
					findChildLinear(key, entries)
				}
			})
			b.Run("rep=map", func(b *testing.B) {
				m := map[string]any{}
				for _, c := range list {
					m[c] = nil
				}
				var x any
				b.ResetTimer()
				for i := 0; i < b.N; i++ {
					x = m[key]
				}
				_ = x
			})

	// This function can be called from the init function of a plugin.
	// Drop a placeholder in the map so subsequent opens can wait on it.
	p := &Plugin{
		pluginpath: pluginpath,
		loaded:     make(chan struct{}),
	}
	plugins[filepath] = p
	pluginsMu.Unlock()

	doInit(initTasks)

	// Fill out the value of each plugin symbol.
	updatedSyms := map[string]any{}
	for symName, sym := range syms {
		isFunc := symName[0] == '.'

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

package p

type Message struct {
	Header map[string][]string
}

func f() {
	m := Message{Header: map[string][]string{}}
	m.Header[""] = append([]string(m.Header[""]), "")
	_ = m

		}
		var info *Info
		if writeInfo {
			info = &Info{
				Types:      make(map[syntax.Expr]TypeAndValue),
				Defs:       make(map[*syntax.Name]Object),
				Uses:       make(map[*syntax.Name]Object),
				Implicits:  make(map[syntax.Node]Object),
				Selections: make(map[*syntax.SelectorExpr]*Selection),
				Scopes:     make(map[syntax.Node]*Scope),
			}
		}
		if _, err := conf.Check(path, files, info); err != nil {

	id := rtcov.AddMeta(p, dlen, hash, pkgpath, pkgid, cmode, cgran)
	if id == 0 {
		throw("runtime.addCovMeta: coverage package map collision")
	}
	return id

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

package p

func _[T interface{~map[string]int}](x T) {
	_ = x == nil
}

// simplified test case from issue

type PathParamsConstraint interface {
        ~map[string]string | ~[]struct{key, value string}
}

type PathParams[T PathParamsConstraint] struct {
	t T
}

func (pp *PathParams[T]) IsNil() bool {