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Diffstat (limited to 'test/alias2.go')
-rw-r--r-- | test/alias2.go | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/test/alias2.go b/test/alias2.go new file mode 100644 index 0000000..1c141ac --- /dev/null +++ b/test/alias2.go @@ -0,0 +1,104 @@ +// errorcheck + +// 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. + +// Test basic restrictions on type aliases. + +package p + +import ( + "reflect" + . "reflect" +) + +type T0 struct{} + +// Valid type alias declarations. + +type _ = T0 +type _ = int +type _ = struct{} +type _ = reflect.Value +type _ = Value + +type ( + A0 = T0 + A1 = int + A2 = struct{} + A3 = reflect.Value + A4 = Value + A5 = Value + + N0 A0 +) + +// Methods can be declared on the original named type and the alias. +func (T0) m1() {} // GCCGO_ERROR "previous" +func (*T0) m1() {} // ERROR "method redeclared: T0\.m1|redefinition of .m1." +func (A0) m1() {} // ERROR "T0\.m1 redeclared in this block|redefinition of .m1." +func (A0) m1() {} // ERROR "T0\.m1 redeclared in this block|redefinition of .m1." +func (A0) m2() {} + +// Type aliases and the original type name can be used interchangeably. +var _ A0 = T0{} +var _ T0 = A0{} + +// But aliases and original types cannot be used with new types based on them. +var _ N0 = T0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type" +var _ N0 = A0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type" + +var _ A5 = Value{} + +var _ interface { + m1() + m2() +} = T0{} + +var _ interface { + m1() + m2() +} = A0{} + +func _() { + type _ = T0 + type _ = int + type _ = struct{} + type _ = reflect.Value + type _ = Value + + type ( + A0 = T0 + A1 = int + A2 = struct{} + A3 = reflect.Value + A4 = Value + A5 Value + + N0 A0 + ) + + var _ A0 = T0{} + var _ T0 = A0{} + + var _ N0 = T0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type" + var _ N0 = A0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type" + + var _ A5 = Value{} // ERROR "cannot use reflect\.Value{} \(type reflect.Value\) as type A5 in assignment|incompatible type" +} + +// Invalid type alias declarations. + +type _ = reflect.ValueOf // ERROR "reflect.ValueOf is not a type|expected type" + +func (A1) m() {} // ERROR "cannot define new methods on non-local type int|may not define methods on non-local type" +func (A2) m() {} // ERROR "invalid receiver type" +func (A3) m() {} // ERROR "cannot define new methods on non-local type reflect.Value|may not define methods on non-local type" +func (A4) m() {} // ERROR "cannot define new methods on non-local type reflect.Value|may not define methods on non-local type" + +type B1 = struct{} + +func (B1) m() {} // ERROR "invalid receiver type" + +// TODO(gri) expand |