github.com/zach-klippenstein/go@v0.0.0-20150108044943-fcfbeb3adf58/test/const4.go (about)

     1  // run
     2  
     3  // Copyright 2011 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test len constants and non-constants, http://golang.org/issue/3244.
     8  
     9  package main
    10  
    11  var b struct {
    12  	a [10]int
    13  }
    14  
    15  var m map[string][20]int
    16  
    17  var s [][30]int
    18  
    19  const (
    20  	n1 = len(b.a)
    21  	n2 = len(m[""])
    22  	n3 = len(s[10])
    23  )
    24  
    25  // Non-constants (see also const5.go).
    26  var (
    27  	n4 = len(f())
    28  	n5 = len(<-c)
    29  	n6 = cap(g())
    30  	n7 = cap(<-c1)
    31  )
    32  
    33  var calledF = false
    34  
    35  func f() *[40]int {
    36  	calledF = true
    37  	return nil
    38  }
    39  
    40  var c = func() chan *[50]int {
    41  	c := make(chan *[50]int, 2)
    42  	c <- nil
    43  	c <- new([50]int)
    44  	return c
    45  }()
    46  
    47  var calledG = false
    48  
    49  func g() *[60]int {
    50  	calledG = true
    51  	return nil
    52  }
    53  
    54  var c1 = func() chan *[70]int {
    55  	c := make(chan *[70]int, 2)
    56  	c <- nil
    57  	c <- new([70]int)
    58  	return c
    59  }()
    60  
    61  func main() {
    62  	if n1 != 10 || n2 != 20 || n3 != 30 || n4 != 40 || n5 != 50 || n6 != 60 || n7 != 70 {
    63  		println("BUG:", n1, n2, n3, n4, n5, n6, n7)
    64  		panic("fail")
    65  	}
    66  	if !calledF {
    67  		println("BUG: did not call f")
    68  		panic("fail")
    69  	}
    70  	if <-c == nil {
    71  		println("BUG: did not receive from c")
    72  		panic("fail")
    73  	}
    74  	if !calledG {
    75  		println("BUG: did not call g")
    76  		panic("fail")
    77  	}
    78  	if <-c1 == nil {
    79  		println("BUG: did not receive from c1")
    80  		panic("fail")
    81  	}
    82  }