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// Copyright 2012 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.
// comparisons
package expr2
func _bool() {
const t = true == true
const f = true == false
_ = t /* ERRORx `operator .* not defined` */ < f
_ = 0 == t /* ERROR "mismatched types untyped int and untyped bool" */
var b bool
var x, y float32
b = x < y
_ = b
_ = struct{b bool}{x < y}
}
// corner cases
var (
v0 = nil == nil // ERROR "operator == not defined on untyped nil"
)
func arrays() {
// basics
var a, b [10]int
_ = a == b
_ = a != b
_ = a /* ERROR "< not defined" */ < b
_ = a == nil /* ERROR "mismatched types" */
type C [10]int
var c C
_ = a == c
type D [10]int
var d D
_ = c == d /* ERROR "mismatched types" */
var e [10]func() int
_ = e /* ERROR "[10]func() int cannot be compared" */ == e
}
func structs() {
// basics
var s, t struct {
x int
a [10]float32
_ bool
}
_ = s == t
_ = s != t
_ = s /* ERROR "< not defined" */ < t
_ = s == nil /* ERROR "mismatched types" */
type S struct {
x int
a [10]float32
_ bool
}
type T struct {
x int
a [10]float32
_ bool
}
var ss S
var tt T
_ = s == ss
_ = ss == tt /* ERROR "mismatched types" */
var u struct {
x int
a [10]map[string]int
}
_ = u /* ERROR "cannot be compared" */ == u
}
func pointers() {
// nil
_ = nil == nil // ERROR "operator == not defined on untyped nil"
_ = nil != nil // ERROR "operator != not defined on untyped nil"
_ = nil /* ERROR "< not defined" */ < nil
_ = nil /* ERROR "<= not defined" */ <= nil
_ = nil /* ERROR "> not defined" */ > nil
_ = nil /* ERROR ">= not defined" */ >= nil
// basics
var p, q *int
_ = p == q
_ = p != q
_ = p == nil
_ = p != nil
_ = nil == q
_ = nil != q
_ = p /* ERROR "< not defined" */ < q
_ = p /* ERROR "<= not defined" */ <= q
_ = p /* ERROR "> not defined" */ > q
_ = p /* ERROR ">= not defined" */ >= q
// various element types
type (
S1 struct{}
S2 struct{}
P1 *S1
P2 *S2
)
var (
ps1 *S1
ps2 *S2
p1 P1
p2 P2
)
_ = ps1 == ps1
_ = ps1 == ps2 /* ERROR "mismatched types" */
_ = ps2 == ps1 /* ERROR "mismatched types" */
_ = p1 == p1
_ = p1 == p2 /* ERROR "mismatched types" */
_ = p1 == ps1
}
func channels() {
// basics
var c, d chan int
_ = c == d
_ = c != d
_ = c == nil
_ = c /* ERROR "< not defined" */ < d
// various element types (named types)
type (
C1 chan int
C1r <-chan int
C1s chan<- int
C2 chan float32
)
var (
c1 C1
c1r C1r
c1s C1s
c1a chan int
c2 C2
)
_ = c1 == c1
_ = c1 == c1r /* ERROR "mismatched types" */
_ = c1 == c1s /* ERROR "mismatched types" */
_ = c1r == c1s /* ERROR "mismatched types" */
_ = c1 == c1a
_ = c1a == c1
_ = c1 == c2 /* ERROR "mismatched types" */
_ = c1a == c2 /* ERROR "mismatched types" */
// various element types (unnamed types)
var (
d1 chan int
d1r <-chan int
d1s chan<- int
d1a chan<- int
d2 chan float32
)
_ = d1 == d1
_ = d1 == d1r
_ = d1 == d1s
_ = d1r == d1s /* ERROR "mismatched types" */
_ = d1 == d1a
_ = d1a == d1
_ = d1 == d2 /* ERROR "mismatched types" */
_ = d1a == d2 /* ERROR "mismatched types" */
}
// for interfaces test
type S1 struct{}
type S11 struct{}
type S2 struct{}
func (*S1) m() int
func (*S11) m() int
func (*S11) n()
func (*S2) m() float32
func interfaces() {
// basics
var i, j interface{ m() int }
_ = i == j
_ = i != j
_ = i == nil
_ = i /* ERROR "< not defined" */ < j
// various interfaces
var ii interface { m() int; n() }
var k interface { m() float32 }
_ = i == ii
_ = i == k /* ERROR "mismatched types" */
// interfaces vs values
var s1 S1
var s11 S11
var s2 S2
_ = i == 0 /* ERROR "cannot convert" */
_ = i == s1 /* ERROR "mismatched types" */
_ = i == &s1
_ = i == &s11
_ = i == s2 /* ERROR "mismatched types" */
_ = i == & /* ERROR "mismatched types" */ s2
// issue #28164
// testcase from issue
_ = interface{}(nil) == [ /* ERROR "slice can only be compared to nil" */ ]int(nil)
// related cases
var e interface{}
var s []int
var x int
_ = e == s // ERROR "slice can only be compared to nil"
_ = s /* ERROR "slice can only be compared to nil" */ == e
_ = e /* ERROR "operator < not defined on interface" */ < x
_ = x < e // ERROR "operator < not defined on interface"
}
func slices() {
// basics
var s []int
_ = s == nil
_ = s != nil
_ = s /* ERROR "< not defined" */ < nil
// slices are not otherwise comparable
_ = s /* ERROR "slice can only be compared to nil" */ == s
_ = s /* ERROR "< not defined" */ < s
}
func maps() {
// basics
var m map[string]int
_ = m == nil
_ = m != nil
_ = m /* ERROR "< not defined" */ < nil
// maps are not otherwise comparable
_ = m /* ERROR "map can only be compared to nil" */ == m
_ = m /* ERROR "< not defined" */ < m
}
func funcs() {
// basics
var f func(int) float32
_ = f == nil
_ = f != nil
_ = f /* ERROR "< not defined" */ < nil
// funcs are not otherwise comparable
_ = f /* ERROR "func can only be compared to nil" */ == f
_ = f /* ERROR "< not defined" */ < f
}