1// errorcheck
2
3// Copyright 2009 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// Verify that illegal assignments with both explicit and implicit conversions of literals are detected.
8// Does not compile.
9
10package main
11
12// explicit conversion of constants
13var x1 = string(1)
14var x2 string = string(1)
15var x3 = int(1.5)     // ERROR "convert|truncate"
16var x4 int = int(1.5) // ERROR "convert|truncate"
17var x5 = "a" + string(1)
18var x6 = int(1e100)      // ERROR "overflow"
19var x7 = float32(1e1000) // ERROR "overflow"
20
21// implicit conversions merit scrutiny
22var s string
23var bad1 string = 1  // ERROR "conver|incompatible|invalid|cannot"
24var bad2 = s + 1     // ERROR "conver|incompatible|invalid"
25var bad3 = s + 'a'   // ERROR "conver|incompatible|invalid"
26var bad4 = "a" + 1   // ERROR "literals|incompatible|convert|invalid"
27var bad5 = "a" + 'a' // ERROR "literals|incompatible|convert|invalid"
28
29var bad6 int = 1.5       // ERROR "convert|truncate"
30var bad7 int = 1e100     // ERROR "overflow"
31var bad8 float32 = 1e200 // ERROR "overflow"
32
33// but these implicit conversions are okay
34var good1 string = "a"
35var good2 int = 1.0
36var good3 int = 1e9
37var good4 float64 = 1e20
38
39// explicit conversion of string is okay
40var _ = []rune("abc")
41var _ = []byte("abc")
42
43// implicit is not
44var _ []int = "abc"  // ERROR "cannot use|incompatible|invalid"
45var _ []byte = "abc" // ERROR "cannot use|incompatible|invalid"
46
47// named string is okay
48type Tstring string
49
50var ss Tstring = "abc"
51var _ = []rune(ss)
52var _ = []byte(ss)
53
54// implicit is still not
55var _ []rune = ss // ERROR "cannot use|incompatible|invalid"
56var _ []byte = ss // ERROR "cannot use|incompatible|invalid"
57
58// named slice is now ok
59type Trune []rune
60type Tbyte []byte
61
62var _ = Trune("abc") // ok
63var _ = Tbyte("abc") // ok
64
65// implicit is still not
66var _ Trune = "abc" // ERROR "cannot use|incompatible|invalid"
67var _ Tbyte = "abc" // ERROR "cannot use|incompatible|invalid"
68