https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30060
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
clang gives a much better diagnostic for sure:
<source>:10:20: error: must use 'class' tag to refer to type 'foo' in this
scope
foo *a=new foo;
^
class
<source>:2:9: note: class 'foo' is hidden by a non-type declaration of 'foo'
here
foo = 1
^
<source>:10:20: error: allocation of incomplete type 'class foo'
foo *a=new foo;
^~~
<source>:10:20: note: forward declaration of 'foo'
<source>:10:14: error: use of undeclared identifier 'a'
foo *a=new foo;
^
