https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84186
Bug ID: 84186
Summary: nested template qualified-id not parsed correctly
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: smw at gcc dot gnu.org
Target Milestone: ---
OK, bear with me on this one, but it appears like a nested qualified-id that is
a simple-template-id confuses the parser, or something.
Here's some code.
template<char k> struct N {
struct S1 { // not a template class
typedef short X;
template<char p> struct S11 {
int a[sizeof(typename N<k>::S1::X*)]; // OK
};
};
template<class P> struct S2 { // woah, a class template
typedef short X;
template<char p> struct S21 {
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
};
};
};
That snippet gets accepted by ICC, MSVC, clang, and pretty much every other
compiler I tested on, bug GCC (all versions, up to and including 8.0.1
20180202) reject it [-std=c++14 -O0 -Wall -pedantic
-fdiagnostics-generate-patch] with the following diagnostic output.
<source>:14:45: error: 'typename N<k>::S2' names 'template<char k>
template<class P> struct N<k>::S2', which is not a type
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
^
<source>:14:41: error: 'typename N<k>::S2' names 'template<char k>
template<class P> struct N<k>::S2', which is not a type
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
^~~~~
<source>:14:46: error: expected '(' before '::' token
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
^~
(
<source>:14:46: error: expected ')' before '::' token
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
~ ^~
)
<source>:14:52: error: expected ']' before ';' token
int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
^
]
--- <source>
+++ <source>
@@ -11,7 +11,7 @@
typedef short X;
template<char p> struct S21 {
- int a[sizeof(typename N<k>::S2<P>::X*)]; // not OK
+ int a[sizeof(typename N<k>::S2<P>()::X*)]]; // not OK
};
};
};
Compiler returned: 1
