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// Copyright 2016 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.
// type aliases
package decls4
type (
T0 [10]int
T1 []byte
T2 struct {
x int
}
T3 interface{
m() T2
}
T4 func(int, T0) chan T2
)
type (
Ai = int
A0 = T0
A1 = T1
A2 = T2
A3 = T3
A4 = T4
A10 = [10]int
A11 = []byte
A12 = struct {
x int
}
A13 = interface{
m() A2
}
A14 = func(int, A0) chan A2
)
// check assignment compatibility due to equality of types
var (
xi_ int
ai Ai = xi_
x0 T0
a0 A0 = x0
x1 T1
a1 A1 = x1
x2 T2
a2 A2 = x2
x3 T3
a3 A3 = x3
x4 T4
a4 A4 = x4
)
// alias receiver types
func (Ai /* ERROR "cannot define new methods on non-local type int" */) m1() {}
func (T0) m1() {}
func (A0) m1 /* ERROR "already declared" */ () {}
func (A0) m2 () {}
func (A3 /* ERROR "invalid receiver" */ ) m1 () {}
func (A10 /* ERROR "invalid receiver" */ ) m1() {}
// x0 has methods m1, m2 declared via receiver type names T0 and A0
var _ interface{ m1(); m2() } = x0
// alias receiver types (test case for issue #23042)
type T struct{}
var (
_ = T.m
_ = T{}.m
_ interface{m()} = T{}
)
var (
_ = T.n
_ = T{}.n
_ interface{m(); n()} = T{}
)
type U = T
func (U) m() {}
// alias receiver types (long type declaration chains)
type (
V0 = V1
V1 = (V2)
V2 = ((V3))
V3 = T
)
func (V0) m /* ERROR "already declared" */ () {}
func (V1) n() {}
// alias receiver types (invalid due to cycles)
type (
W0 /* ERROR "invalid recursive type" */ = W1
W1 = (W2)
W2 = ((W0))
)
func (W0) m() {} // no error expected (due to above cycle error)
func (W1) n() {}
// alias receiver types (invalid due to builtin underlying type)
type (
B0 = B1
B1 = B2
B2 = int
)
func (B0 /* ERROR "cannot define new methods on non-local type int" */ ) m() {}
func (B1 /* ERROR "cannot define new methods on non-local type int" */ ) n() {}
// cycles
type (
C2 /* ERROR "invalid recursive type" */ = C2
C3 /* ERROR "invalid recursive type" */ = C4
C4 = C3
C5 struct {
f *C6
}
C6 = C5
C7 /* ERROR "invalid recursive type" */ struct {
f C8
}
C8 = C7
)
// embedded fields
var (
s0 struct { T0 }
s1 struct { A0 } = s0 /* ERROR "cannot use" */ // embedded field names are different
)
// embedding and lookup of fields and methods
func _(s struct{A0}) { s.A0 = x0 }
type eX struct{xf int}
func (eX) xm()
type eY = struct{eX} // field/method set of eY includes xf, xm
type eZ = *struct{eX} // field/method set of eZ includes xf, xm
type eA struct {
eX // eX contributes xf, xm to eA
}
type eA2 struct {
*eX // *eX contributes xf, xm to eA
}
type eB struct {
eY // eY contributes xf, xm to eB
}
type eB2 struct {
*eY // *eY contributes xf, xm to eB
}
type eC struct {
eZ // eZ contributes xf, xm to eC
}
var (
_ = eA{}.xf
_ = eA{}.xm
_ = eA2{}.xf
_ = eA2{}.xm
_ = eB{}.xf
_ = eB{}.xm
_ = eB2{}.xf
_ = eB2{}.xm
_ = eC{}.xf
_ = eC{}.xm
)
// ambiguous selectors due to embedding via type aliases
type eD struct {
eY
eZ
}
var (
_ = eD{}.xf /* ERROR "ambiguous selector eD{}.xf" */
_ = eD{}.xm /* ERROR "ambiguous selector eD{}.xm" */
)
var (
_ interface{ xm() } = eD /* ERROR "ambiguous selector eD.xm" */ {}
)