mirror of
https://github.com/golang/go
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51 lines
862 B
Go
51 lines
862 B
Go
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// run
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// Copyright 2023 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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package main
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import (
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"strings"
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"unsafe"
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)
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func shift[T any]() int64 {
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return 1 << unsafe.Sizeof(*new(T))
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}
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func div[T any]() uintptr {
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return 1 / unsafe.Sizeof(*new(T))
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}
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func add[T any]() int64 {
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return 1<<63 - 1 + int64(unsafe.Sizeof(*new(T)))
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}
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func main() {
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shift[[62]byte]()
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shift[[63]byte]()
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shift[[64]byte]()
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shift[[100]byte]()
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shift[[1e6]byte]()
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add[[1]byte]()
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shouldPanic("divide by zero", func() { div[[0]byte]() })
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}
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func shouldPanic(str string, f func()) {
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defer func() {
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err := recover()
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if err == nil {
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panic("did not panic")
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}
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s := err.(error).Error()
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if !strings.Contains(s, str) {
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panic("got panic " + s + ", want " + str)
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}
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}()
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f()
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}
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