mirror of
https://github.com/golang/go
synced 2024-11-16 21:14:44 -07:00
7ee35cb301
"cannot assign to" compiler errors are very laconic: they never explain why the lhs cannot be assigned to (with one exception, when assigning to a struct field in a map). This change makes them a little more specific, in two more cases: when assigning to a string, or to a const; by giving a very brief reason why the lhs cannot be assigned to. Change-Id: I244cca7fc3c3814e00e0ccadeec62f747c293979 Reviewed-on: https://go-review.googlesource.com/c/go/+/255199 Trust: Alberto Donizetti <alb.donizetti@gmail.com> Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
34 lines
1.0 KiB
Go
34 lines
1.0 KiB
Go
// errorcheck
|
|
|
|
// Copyright 2020 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.
|
|
|
|
// Test "cannot assign" errors
|
|
|
|
package main
|
|
|
|
func main() {
|
|
var s string = "hello"
|
|
s[1:2] = "a" // ERROR "cannot assign to .* \(strings are immutable\)"
|
|
s[3] = "b" // ERROR "cannot assign to .* \(strings are immutable\)"
|
|
|
|
const n int = 1
|
|
const cs string = "hello"
|
|
n = 2 // ERROR "cannot assign to .* \(declared const\)"
|
|
cs = "hi" // ERROR "cannot assign to .* \(declared const\)"
|
|
true = false // ERROR "cannot assign to .* \(declared const\)"
|
|
|
|
var m map[int]struct{ n int }
|
|
m[0].n = 7 // ERROR "cannot assign to struct field .* in map$"
|
|
|
|
1 = 7 // ERROR "cannot assign to 1$"
|
|
"hi" = 7 // ERROR `cannot assign to "hi"$`
|
|
nil = 7 // ERROR "cannot assign to nil$"
|
|
len("") = 7 // ERROR `cannot assign to len\(""\)$`
|
|
[]int{} = nil // ERROR "cannot assign to \[\]int\{\}$"
|
|
|
|
var x int = 7
|
|
x + 1 = 7 // ERROR "cannot assign to x \+ 1$"
|
|
}
|