https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57632
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #5) > I agree with comment 3 that the current diagnostic is poor: Oh I missed that. > > #include <new> > void* operator new(std::size_t mem) throw(std::bad_alloc); > void* operator new(std::size_t mem) throw(std::bad_alloc); > > > g++ -std=c++11 -c new.cc -Wno-deprecated > new.cc:3:7: error: declaration of ‘void* operator new(std::size_t) throw > (std::bad_alloc)’ has a different exception specifier > 3 | void* operator new(std::size_t mem) throw(std::bad_alloc); > | ^~~~~~~~ > new.cc:2:7: note: from previous declaration ‘void* operator new(std::size_t)’ > 2 | void* operator new(std::size_t mem) throw(std::bad_alloc); > | ^~~~~~~~ > Reduced testcase for that: void f(void); void f(void) throw(int); void f(void) throw(int); Noexcept has the same issue: void g(void); void g(void) noexcept; void g(void) noexcept; I suspect what happens is the following when we merge the two decls we chose the new decl for the location but we remove the exception specifier/noexcept (confirmed by swapping the first two decls and seeing the error again).
