https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113830
Bug ID: 113830
Summary: GCC accepts invalid code when instantiating the local
class inside a function
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: wangbopku15 at gmail dot com
Target Milestone: ---
The following invalid code is accepted by both x86-64 gcc-trunk and x86-64
gcc-13.2:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
template<typename T> void f() {
struct S { void g(int n = T::unknown){}; };
}
template void f<int>();
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The code is invalid because the type name "int" passed in the template function
specialization does not contain the member "unknown":
It appears that if a template function has an internally defined local class
that uses a dependent name in its member function, it can cause the compiler's
name-binding process to get into trouble.
If we compile it via clang-trunk, it rejects the code with the error message:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<source>:2:29: error: type 'int' cannot be used prior to '::' because it has no
members
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Please see the godbolt to reproduce it: https://godbolt.org/z/nb3rE8s5a
