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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
40 lines
665 B
Go
40 lines
665 B
Go
// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG: interface/noeq
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// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Interface values containing types that cannot be compared for equality.
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package main
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func main() {
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cmp(1)
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var (
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m map[int]int
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s struct{ x []int }
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f func()
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)
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noCmp(m)
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noCmp(s)
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noCmp(f)
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}
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func cmp(x interface{}) bool {
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return x == x
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}
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func noCmp(x interface{}) {
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shouldPanic(func() { cmp(x) })
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}
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func shouldPanic(f func()) {
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defer func() {
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if recover() == nil {
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panic("function should panic")
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}
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}()
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f()
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}
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