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Incorporate class fields into recursive-type check

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Noticed while investigating issue 2718 that the typechecker allowed
some non-instantiable types involving classes. This wasn't the root of
2718, but fixed it anyway.
This commit is contained in:
Tim Chevalier 2012-06-25 22:10:28 -07:00
parent d513d9893e
commit cf69604551
2 changed files with 21 additions and 1 deletions
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10
src/rustc/middle/ty.rs
View file

@ -1218,7 +1218,6 @@ fn type_needs_drop(cx: ctxt, ty: t) -> bool {
accum
}
}
ty_tup(elts) {
for elts.each {|m| if type_needs_drop(cx, m) { accum = true; } }
accum
@ -1720,6 +1719,7 @@ fn is_instantiable(cx: ctxt, r_ty: t) -> bool {
fn type_structurally_contains(cx: ctxt, ty: t, test: fn(sty) -> bool) ->
bool {
let sty = get(ty).struct;
#debug("type_structurally_contains: %s", ty_to_str(cx, ty));
if test(sty) { ret true; }
alt sty {
ty_enum(did, substs) {
@ -1737,6 +1737,14 @@ fn type_structurally_contains(cx: ctxt, ty: t, test: fn(sty) -> bool) ->
}
ret false;
}
ty_class(did, substs) {
for lookup_class_fields(cx, did).each {|field|
let ft = lookup_field_type(cx, did, field.id, substs);
if type_structurally_contains(cx, ft, test) { ret true; }
}
ret false;
}
ty_tup(ts) {
for ts.each {|tt|
if type_structurally_contains(cx, tt, test) { ret true; }

12
src/test/compile-fail/issue-2718-a.rs Normal file
View file

@ -0,0 +1,12 @@
class send_packet<T: copy> {
let p: T;
new(p: T) { self.p = p; }
}
mod pingpong {
type ping = send_packet<pong>;
enum pong = send_packet<ping>; //! ERROR illegal recursive enum type; wrap the inner value in a box to make it representable
}
fn main() {}