https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85500
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is not a valid bug report, see https://gcc.gnu.org/bugs/ for what we require. (In reply to ASA from comment #0) > When initializing an auto variable from a function identifier, GNU C++ is > incorrectly defining a new function. > > The statement: > > auto variable_name = function_name; > > Will define a function or nested function depending on the scope of > reference named variable_name. This is not a pedantically correct > interpretation of the C++ source code as only variables can be initialized. Here's a complete program: #include <type_traits> int function_name() { return 0; } auto variable_name = function_name; static_assert(std::is_pointer<decltype(variable_name)>::value, ""); int main() { return (*variable_name)(); } This shows that your statement is not creating a new function, it's a pointer to function. You cannot copy functions or declare them as variables, so the 'auto' declaration performs function-to-pointer decay and so deduces a function pointer type not a function type. > > Also be careful in your bug correction: > > auto function_name; > > Should still be treated as a function declaration when initialization is not > present (as of C++14). No, that's not valid as a function declaration.