1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
// errorcheck
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Verify that illegal assignments with both explicit and implicit conversions of literals are detected.
// Does not compile.
package main
// explicit conversion of constants
var x1 = string(1)
var x2 string = string(1)
var x3 = int(1.5) // ERROR "convert|truncate"
var x4 int = int(1.5) // ERROR "convert|truncate"
var x5 = "a" + string(1)
var x6 = int(1e100) // ERROR "overflow"
var x7 = float32(1e1000) // ERROR "overflow"
// implicit conversions merit scrutiny
var s string
var bad1 string = 1 // ERROR "conver|incompatible|invalid|cannot"
var bad2 = s + 1 // ERROR "conver|incompatible|invalid"
var bad3 = s + 'a' // ERROR "conver|incompatible|invalid"
var bad4 = "a" + 1 // ERROR "literals|incompatible|convert|invalid"
var bad5 = "a" + 'a' // ERROR "literals|incompatible|convert|invalid"
var bad6 int = 1.5 // ERROR "convert|truncate"
var bad7 int = 1e100 // ERROR "overflow"
var bad8 float32 = 1e200 // ERROR "overflow"
// but these implicit conversions are okay
var good1 string = "a"
var good2 int = 1.0
var good3 int = 1e9
var good4 float64 = 1e20
// explicit conversion of string is okay
var _ = []rune("abc")
var _ = []byte("abc")
// implicit is not
var _ []int = "abc" // ERROR "cannot use|incompatible|invalid"
var _ []byte = "abc" // ERROR "cannot use|incompatible|invalid"
// named string is okay
type Tstring string
var ss Tstring = "abc"
var _ = []rune(ss)
var _ = []byte(ss)
// implicit is still not
var _ []rune = ss // ERROR "cannot use|incompatible|invalid"
var _ []byte = ss // ERROR "cannot use|incompatible|invalid"
// named slice is now ok
type Trune []rune
type Tbyte []byte
var _ = Trune("abc") // ok
var _ = Tbyte("abc") // ok
// implicit is still not
var _ Trune = "abc" // ERROR "cannot use|incompatible|invalid"
var _ Tbyte = "abc" // ERROR "cannot use|incompatible|invalid"
|
