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// Copyright 2013 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.
package constdecl
import "math"
import "unsafe"
var v int
// Const decls must be initialized by constants.
const _ = v /* ERROR "not constant" */
const _ = math /* ERROR "not constant" */ .Sin(0)
const _ = int /* ERROR "not an expression" */
func _() {
const _ = v /* ERROR "not constant" */
const _ = math /* ERROR "not constant" */ .Sin(0)
const _ = int /* ERROR "not an expression" */
}
// Identifier and expression arity must match.
const _ /* ERROR "missing init expr for _" */
const _ = 1, 2 /* ERROR "extra init expr 2" */
const _ /* ERROR "missing init expr for _" */ int
const _ int = 1, 2 /* ERROR "extra init expr 2" */
const (
_ /* ERROR "missing init expr for _" */
_ = 1, 2 /* ERROR "extra init expr 2" */
_ /* ERROR "missing init expr for _" */ int
_ int = 1, 2 /* ERROR "extra init expr 2" */
)
const (
_ = 1
_
_, _ /* ERROR "missing init expr for _" */
_
)
const (
_, _ = 1, 2
_, _
_ /* ERROR "extra init expr at" */
_, _
_, _, _ /* ERROR "missing init expr for _" */
_, _
)
func _() {
const _ /* ERROR "missing init expr for _" */
const _ = 1, 2 /* ERROR "extra init expr 2" */
const _ /* ERROR "missing init expr for _" */ int
const _ int = 1, 2 /* ERROR "extra init expr 2" */
const (
_ /* ERROR "missing init expr for _" */
_ = 1, 2 /* ERROR "extra init expr 2" */
_ /* ERROR "missing init expr for _" */ int
_ int = 1, 2 /* ERROR "extra init expr 2" */
)
const (
_ = 1
_
_, _ /* ERROR "missing init expr for _" */
_
)
const (
_, _ = 1, 2
_, _
_ /* ERROR "extra init expr at" */
_, _
_, _, _ /* ERROR "missing init expr for _" */
_, _
)
}
// Test case for constant with invalid initialization.
// Caused panic because the constant value was not set up (gri - 7/8/2014).
func _() {
const (
x string = missing /* ERROR "undefined" */
y = x + ""
)
}
// Test case for constants depending on function literals (see also #22992).
const A /* ERROR "initialization cycle" */ = unsafe.Sizeof(func() { _ = A })
func _() {
// The function literal below must not see a.
const a = unsafe.Sizeof(func() { _ = a /* ERROR "undefined" */ })
const b = unsafe.Sizeof(func() { _ = a })
// The function literal below must not see x, y, or z.
const x, y, z = 0, 1, unsafe.Sizeof(func() { _ = x /* ERROR "undefined" */ + y /* ERROR "undefined" */ + z /* ERROR "undefined" */ })
}
// Test cases for errors in inherited constant initialization expressions.
// Errors related to inherited initialization expressions must appear at
// the constant identifier being declared, not at the original expression
// (issues #42991, #42992).
const (
_ byte = 255 + iota
/* some gap */
_ // ERROR "overflows"
/* some gap */
/* some gap */ _ /* ERROR "overflows" */; _ /* ERROR "overflows" */
/* some gap */
_ = 255 + iota
_ = byte /* ERROR "overflows" */ (255) + iota
_ /* ERROR "overflows" */
)
// Test cases from issue.
const (
ok = byte(iota + 253)
bad
barn
bard // ERROR "cannot convert"
)
const (
c = len([1 - iota]int{})
d
e // ERROR "invalid array length"
f // ERROR "invalid array length"
)
// Test that identifiers in implicit (omitted) RHS
// expressions of constant declarations are resolved
// in the correct context; see issues #49157, #53585.
const X = 2
func _() {
const (
A = iota // 0
iota = iota // 1
B // 1 (iota is declared locally on prev. line)
C // 1
)
assert(A == 0 && B == 1 && C == 1)
const (
X = X + X
Y
Z = iota
)
assert(X == 4 && Y == 8 && Z == 1)
}
// TODO(gri) move extra tests from testdata/const0.src into here