https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124781
Bug ID: 124781
Summary: [modules] Exported IIFE has error: exporting
declaration ‘...’ declared in unnamed namespace
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: marcel at laverdet dot com
Target Milestone: ---
Minimal-ish repro:
module;
#include <type_traits>
export module foo;
template <auto Type>
using type_t = decltype(Type)::type;
export using xx = type_t<[]() consteval -> auto {
using yy = int;
return std::type_identity<int>{};
}()>;
root[15:33:29] [/workspace] $ /root/gcc-16/bin/g++ -std=c++26 -Wall -fmodules
-c a.cc
a.cc: In lambda function:
a.cc:9:15: error: exporting declaration ‘using yy = int’ declared in unnamed
namespace
9 | using yy = int;
| ^~
Commenting out the nested `using yy` declaration (which is not exported) fixes
it. Assigning the function to a temporary also fixes it.
