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45 lines
1.3 KiB
Go
45 lines
1.3 KiB
Go
// compile
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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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// Test legal shifts.
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// Issue 1708, legal cases.
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// Compiles but does not run.
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package p
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func f(x int) int { return 0 }
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func g(x interface{}) int { return 0 }
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func h(x float64) int { return 0 }
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// from the spec
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var (
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s uint = 33
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i = 1 << s // 1 has type int
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j int32 = 1 << s // 1 has type int32; j == 0
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k = uint64(1 << s) // 1 has type uint64; k == 1<<33
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m int = 1.0 << s // legal: 1.0 has type int
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w int64 = 1.0 << 33 // legal: 1.0<<33 is a constant shift expression
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)
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// non-constant shift expressions
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var (
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a1 int = 2.0 << s // typeof(2.0) is int in this context => legal shift
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d1 = f(2.0 << s) // typeof(2.0) is int in this context => legal shift
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)
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// constant shift expressions
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const c uint = 5
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var (
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a2 int = 2.0 << c // a2 == 64 (type int)
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b2 = 2.0 << c // b2 == 64 (untyped integer)
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_ = f(b2) // verify b2 has type int
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c2 float64 = 2 << c // c2 == 64.0 (type float64)
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d2 = f(2.0 << c) // == f(64)
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e2 = g(2.0 << c) // == g(int(64))
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f2 = h(2 << c) // == h(float64(64.0))
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)
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