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31 lines
786 B
Go
31 lines
786 B
Go
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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 77.
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// Netflag demonstrates an integer type used as a bit field.
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package main
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import (
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"fmt"
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. "net"
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)
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//!+
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func IsUp(v Flags) bool { return v&FlagUp == FlagUp }
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func TurnDown(v *Flags) { *v &^= FlagUp }
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func SetBroadcast(v *Flags) { *v |= FlagBroadcast }
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func IsCast(v Flags) bool { return v&(FlagBroadcast|FlagMulticast) != 0 }
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func main() {
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var v Flags = FlagMulticast | FlagUp
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fmt.Printf("%b %t\n", v, IsUp(v)) // "10001 true"
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TurnDown(&v)
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fmt.Printf("%b %t\n", v, IsUp(v)) // "10000 false"
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SetBroadcast(&v)
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fmt.Printf("%b %t\n", v, IsUp(v)) // "10010 false"
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fmt.Printf("%b %t\n", v, IsCast(v)) // "10010 true"
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}
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//!-
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