switch p.tok {
case _Operator, _Star:
switch p.op {
- case Mul, Add, Sub, Not, Xor:
+ case Mul, Add, Sub, Not, Xor, Tilde:
x := new(Operation)
x.pos = p.pos()
x.Op = p.op
// Single-expression type parameter lists and those that don't start
// with a (type parameter) name are considered array sizes.
-// The term must be a valid expression (it could be a type - and then
-// a type-checker will complain - but we don't allow ~ in the expr).
+// The term must be a valid expression (it could be a type incl. a
+// tilde term) but the type-checker will complain.
type (
_[t] t
- _[/* ERROR unexpected ~ */ ~t] t
_[t|t] t
- _[/* ERROR unexpected ~ */ ~t|t] t
- _[t| /* ERROR unexpected ~ */ ~t] t
- _[/* ERROR unexpected ~ */ ~t|~t] t
+
+ // These are invalid and the type-checker will complain.
+ _[~t] t
+ _[~t|t] t
+ _[t|~t] t
+ _[~t|~t] t
)
type (
x.typ = ch.elem
check.hasCallOrRecv = true
return
+
+ case syntax.Tilde:
+ // Provide a better error position and message than what check.op below could do.
+ check.error(e, "cannot use ~ outside of interface or type constraint")
+ x.mode = invalid
+ return
}
if !check.op(unaryOpPredicates, x, e.Op) {
_ = -g /* ERROR 2-valued g */ ()
_ = <-g /* ERROR 2-valued g */ ()
}
+
+// ~ is accepted as unary operator only permitted in interface type elements
+var (
+ _ = ~ /* ERROR cannot use ~ outside of interface or type constraint */ 0
+ _ = ~ /* ERROR cannot use ~ outside of interface or type constraint */ "foo"
+ _ = ~ /* ERROR cannot use ~ outside of interface or type constraint */ i0
+)
\ No newline at end of file
type _[P *struct /* ERROR "not an expression" */ {}| int /* ERROR "not an expression" */ ] struct{}
// The following fails to parse, due to the '~'
-type _[P *struct /* ERROR "not an expression" */ {}|~ /* ERROR "unexpected ~" */ int] struct{}
+type _[P *struct /* ERROR "not an expression" */ {}|~int /* ERROR "not an expression" */ ] struct{}
package p
func _(x int) {
- _ = ~x // ERROR "unexpected ~"
+ _ = ~x // unary ~ permitted but the type-checker will complain
}
func _(x int) {