mirror of
https://github.com/golang/go
synced 2024-11-22 05:24:39 -07:00
196b663075
To allow these types as map keys, we must fill in equal and hash functions in their algorithm tables. Structs or arrays that are "just memory", like [2]int, can and do continue to use the AMEM algorithm. Structs or arrays that contain special values like strings or interface values use generated functions for both equal and hash. The runtime helper func runtime.equal(t, x, y) bool handles the general equality case for x == y and calls out to the equal implementation in the algorithm table. For short values (<= 4 struct fields or array elements), the sequence of elementwise comparisons is inlined instead of calling runtime.equal. R=ken, mpimenov CC=golang-dev https://golang.org/cl/5451105
400 lines
6.3 KiB
Go
400 lines
6.3 KiB
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
|
|
|
|
// Copyright 2009 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 main
|
|
|
|
import "unsafe"
|
|
|
|
func use(bool) {}
|
|
|
|
func stringptr(s string) uintptr { return *(*uintptr)(unsafe.Pointer(&s)) }
|
|
|
|
func isfalse(b bool) {
|
|
if b {
|
|
// stack will explain where
|
|
panic("wanted false, got true")
|
|
}
|
|
}
|
|
|
|
func istrue(b bool) {
|
|
if !b {
|
|
// stack will explain where
|
|
panic("wanted true, got false")
|
|
}
|
|
}
|
|
|
|
type T *int
|
|
|
|
func main() {
|
|
var a []int
|
|
var b map[string]int
|
|
|
|
var c string = "hello"
|
|
var d string = "hel" // try to get different pointer
|
|
d = d + "lo"
|
|
if stringptr(c) == stringptr(d) {
|
|
panic("compiler too smart -- got same string")
|
|
}
|
|
|
|
var e = make(chan int)
|
|
|
|
var ia interface{} = a
|
|
var ib interface{} = b
|
|
var ic interface{} = c
|
|
var id interface{} = d
|
|
var ie interface{} = e
|
|
|
|
// these comparisons are okay because
|
|
// string compare is okay and the others
|
|
// are comparisons where the types differ.
|
|
isfalse(ia == ib)
|
|
isfalse(ia == ic)
|
|
isfalse(ia == id)
|
|
isfalse(ib == ic)
|
|
isfalse(ib == id)
|
|
istrue(ic == id)
|
|
istrue(ie == ie)
|
|
|
|
istrue(ia != ib)
|
|
istrue(ia != ic)
|
|
istrue(ia != id)
|
|
istrue(ib != ic)
|
|
istrue(ib != id)
|
|
isfalse(ic != id)
|
|
isfalse(ie != ie)
|
|
|
|
// these are not okay, because there is no comparison on slices or maps.
|
|
//isfalse(a == ib)
|
|
//isfalse(a == ic)
|
|
//isfalse(a == id)
|
|
//isfalse(b == ic)
|
|
//isfalse(b == id)
|
|
|
|
istrue(c == id)
|
|
istrue(e == ie)
|
|
|
|
//isfalse(ia == b)
|
|
isfalse(ia == c)
|
|
isfalse(ia == d)
|
|
isfalse(ib == c)
|
|
isfalse(ib == d)
|
|
istrue(ic == d)
|
|
istrue(ie == e)
|
|
|
|
//istrue(a != ib)
|
|
//istrue(a != ic)
|
|
//istrue(a != id)
|
|
//istrue(b != ic)
|
|
//istrue(b != id)
|
|
isfalse(c != id)
|
|
isfalse(e != ie)
|
|
|
|
//istrue(ia != b)
|
|
istrue(ia != c)
|
|
istrue(ia != d)
|
|
istrue(ib != c)
|
|
istrue(ib != d)
|
|
isfalse(ic != d)
|
|
isfalse(ie != e)
|
|
|
|
// 6g used to let this go through as true.
|
|
var g uint64 = 123
|
|
var h int64 = 123
|
|
var ig interface{} = g
|
|
var ih interface{} = h
|
|
isfalse(ig == ih)
|
|
istrue(ig != ih)
|
|
|
|
// map of interface should use == on interface values,
|
|
// not memory.
|
|
var m = make(map[interface{}]int)
|
|
m[ic] = 1
|
|
m[id] = 2
|
|
if m[c] != 2 {
|
|
println("m[c] = ", m[c])
|
|
panic("bad m[c]")
|
|
}
|
|
|
|
// non-interface comparisons
|
|
{
|
|
c := make(chan int)
|
|
c1 := (<-chan int)(c)
|
|
c2 := (chan<- int)(c)
|
|
istrue(c == c1)
|
|
istrue(c == c2)
|
|
istrue(c1 == c)
|
|
istrue(c2 == c)
|
|
|
|
isfalse(c != c1)
|
|
isfalse(c != c2)
|
|
isfalse(c1 != c)
|
|
isfalse(c2 != c)
|
|
|
|
d := make(chan int)
|
|
isfalse(c == d)
|
|
isfalse(d == c)
|
|
isfalse(d == c1)
|
|
isfalse(d == c2)
|
|
isfalse(c1 == d)
|
|
isfalse(c2 == d)
|
|
|
|
istrue(c != d)
|
|
istrue(d != c)
|
|
istrue(d != c1)
|
|
istrue(d != c2)
|
|
istrue(c1 != d)
|
|
istrue(c2 != d)
|
|
}
|
|
|
|
// named types vs not
|
|
{
|
|
var x = new(int)
|
|
var y T
|
|
var z T = x
|
|
|
|
isfalse(x == y)
|
|
istrue(x == z)
|
|
isfalse(y == z)
|
|
|
|
isfalse(y == x)
|
|
istrue(z == x)
|
|
isfalse(z == y)
|
|
|
|
istrue(x != y)
|
|
isfalse(x != z)
|
|
istrue(y != z)
|
|
|
|
istrue(y != x)
|
|
isfalse(z != x)
|
|
istrue(z != y)
|
|
}
|
|
|
|
// structs
|
|
{
|
|
var x = struct {
|
|
x int
|
|
y string
|
|
}{1, "hi"}
|
|
var y = struct {
|
|
x int
|
|
y string
|
|
}{2, "bye"}
|
|
var z = struct {
|
|
x int
|
|
y string
|
|
}{1, "hi"}
|
|
|
|
isfalse(x == y)
|
|
isfalse(y == x)
|
|
isfalse(y == z)
|
|
isfalse(z == y)
|
|
istrue(x == z)
|
|
istrue(z == x)
|
|
|
|
istrue(x != y)
|
|
istrue(y != x)
|
|
istrue(y != z)
|
|
istrue(z != y)
|
|
isfalse(x != z)
|
|
isfalse(z != x)
|
|
|
|
var m = make(map[struct {
|
|
x int
|
|
y string
|
|
}]int)
|
|
m[x] = 10
|
|
m[y] = 20
|
|
m[z] = 30
|
|
istrue(m[x] == 30)
|
|
istrue(m[y] == 20)
|
|
istrue(m[z] == 30)
|
|
istrue(m[x] != 10)
|
|
isfalse(m[x] != 30)
|
|
isfalse(m[y] != 20)
|
|
isfalse(m[z] != 30)
|
|
isfalse(m[x] == 10)
|
|
|
|
var m1 = make(map[struct {
|
|
x int
|
|
y string
|
|
}]struct {
|
|
x int
|
|
y string
|
|
})
|
|
m1[x] = x
|
|
m1[y] = y
|
|
m1[z] = z
|
|
istrue(m1[x] == z)
|
|
istrue(m1[y] == y)
|
|
istrue(m1[z] == z)
|
|
istrue(m1[x] == x)
|
|
isfalse(m1[x] != z)
|
|
isfalse(m1[y] != y)
|
|
isfalse(m1[z] != z)
|
|
isfalse(m1[x] != x)
|
|
|
|
var ix, iy, iz interface{} = x, y, z
|
|
|
|
isfalse(ix == iy)
|
|
isfalse(iy == ix)
|
|
isfalse(iy == iz)
|
|
isfalse(iz == iy)
|
|
istrue(ix == iz)
|
|
istrue(iz == ix)
|
|
|
|
isfalse(x == iy)
|
|
isfalse(y == ix)
|
|
isfalse(y == iz)
|
|
isfalse(z == iy)
|
|
istrue(x == iz)
|
|
istrue(z == ix)
|
|
|
|
isfalse(ix == y)
|
|
isfalse(iy == x)
|
|
isfalse(iy == z)
|
|
isfalse(iz == y)
|
|
istrue(ix == z)
|
|
istrue(iz == x)
|
|
|
|
istrue(ix != iy)
|
|
istrue(iy != ix)
|
|
istrue(iy != iz)
|
|
istrue(iz != iy)
|
|
isfalse(ix != iz)
|
|
isfalse(iz != ix)
|
|
|
|
istrue(x != iy)
|
|
istrue(y != ix)
|
|
istrue(y != iz)
|
|
istrue(z != iy)
|
|
isfalse(x != iz)
|
|
isfalse(z != ix)
|
|
|
|
istrue(ix != y)
|
|
istrue(iy != x)
|
|
istrue(iy != z)
|
|
istrue(iz != y)
|
|
isfalse(ix != z)
|
|
isfalse(iz != x)
|
|
}
|
|
|
|
// arrays
|
|
{
|
|
var x = [2]string{"1", "hi"}
|
|
var y = [2]string{"2", "bye"}
|
|
var z = [2]string{"1", "hi"}
|
|
|
|
isfalse(x == y)
|
|
isfalse(y == x)
|
|
isfalse(y == z)
|
|
isfalse(z == y)
|
|
istrue(x == z)
|
|
istrue(z == x)
|
|
|
|
istrue(x != y)
|
|
istrue(y != x)
|
|
istrue(y != z)
|
|
istrue(z != y)
|
|
isfalse(x != z)
|
|
isfalse(z != x)
|
|
|
|
var m = make(map[[2]string]int)
|
|
m[x] = 10
|
|
m[y] = 20
|
|
m[z] = 30
|
|
istrue(m[x] == 30)
|
|
istrue(m[y] == 20)
|
|
istrue(m[z] == 30)
|
|
isfalse(m[x] != 30)
|
|
isfalse(m[y] != 20)
|
|
isfalse(m[z] != 30)
|
|
|
|
var ix, iy, iz interface{} = x, y, z
|
|
|
|
isfalse(ix == iy)
|
|
isfalse(iy == ix)
|
|
isfalse(iy == iz)
|
|
isfalse(iz == iy)
|
|
istrue(ix == iz)
|
|
istrue(iz == ix)
|
|
|
|
isfalse(x == iy)
|
|
isfalse(y == ix)
|
|
isfalse(y == iz)
|
|
isfalse(z == iy)
|
|
istrue(x == iz)
|
|
istrue(z == ix)
|
|
|
|
isfalse(ix == y)
|
|
isfalse(iy == x)
|
|
isfalse(iy == z)
|
|
isfalse(iz == y)
|
|
istrue(ix == z)
|
|
istrue(iz == x)
|
|
|
|
istrue(ix != iy)
|
|
istrue(iy != ix)
|
|
istrue(iy != iz)
|
|
istrue(iz != iy)
|
|
isfalse(ix != iz)
|
|
isfalse(iz != ix)
|
|
|
|
istrue(x != iy)
|
|
istrue(y != ix)
|
|
istrue(y != iz)
|
|
istrue(z != iy)
|
|
isfalse(x != iz)
|
|
isfalse(z != ix)
|
|
|
|
istrue(ix != y)
|
|
istrue(iy != x)
|
|
istrue(iy != z)
|
|
istrue(iz != y)
|
|
isfalse(ix != z)
|
|
isfalse(iz != x)
|
|
}
|
|
|
|
shouldPanic(p1)
|
|
shouldPanic(p2)
|
|
shouldPanic(p3)
|
|
shouldPanic(p4)
|
|
}
|
|
|
|
func p1() {
|
|
var a []int
|
|
var ia interface{} = a
|
|
use(ia == ia)
|
|
}
|
|
|
|
func p2() {
|
|
var b []int
|
|
var ib interface{} = b
|
|
use(ib == ib)
|
|
}
|
|
|
|
func p3() {
|
|
var a []int
|
|
var ia interface{} = a
|
|
var m = make(map[interface{}]int)
|
|
m[ia] = 1
|
|
}
|
|
|
|
func p4() {
|
|
var b []int
|
|
var ib interface{} = b
|
|
var m = make(map[interface{}]int)
|
|
m[ib] = 1
|
|
}
|
|
|
|
func shouldPanic(f func()) {
|
|
defer func() {
|
|
if recover() == nil {
|
|
panic("function should panic")
|
|
}
|
|
}()
|
|
f()
|
|
}
|