clang++ error: unknown type name 'nullptr_t'

Question

I recently got a 2020 Macbook air with Ventura on it. I am trying to run some old C++ and for some reason I cannot get it to run. Even running a simple hello world program throws a ton off issues. I am running on the terminal the following program using "clang++ helloworld.cpp"

#include <iostream>

int main() {
    std::cout << "Hello World!";
    return 0;
}

which spits out:

In file included from helloworld.cpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:41:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/ios:221:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:841:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__algorithm/copy.h:12:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__algorithm/unwrap_iter.h:13:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__iterator/iterator_traits.h:14:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__iterator/incrementable_traits.h:15:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/concepts:133:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__concepts/arithmetic.h:15:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/type_traits:421:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__functional/invoke.h:15:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__type_traits/apply_cv.h:16:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__type_traits/remove_reference.h:13:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cstddef:50:9: error: no member named 'nullptr_t' in the global namespace
using ::nullptr_t;
      ~~^
In file included from helloworld.cpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:41:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/ios:221:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:841:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__algorithm/copy.h:12:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__algorithm/unwrap_iter.h:13:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__iterator/iterator_traits.h:14:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__iterator/incrementable_traits.h:15:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/concepts:133:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__concepts/arithmetic.h:15:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/type_traits:452:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__type_traits/is_compound.h:14:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__type_traits/is_fundamental.h:14:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__type_traits/is_null_pointer.h:24:49: error: use of undeclared identifier 'nullptr_t'
template <>          struct __is_nullptr_t_impl<nullptr_t> : public true_type {};
                                                ^
In file included from helloworld.cpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:41:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/ios:221:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:848:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/allocator.h:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/new:94:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/exception:149:45: error: field has incomplete type 'std::exception_ptr'
    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
                                            ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/exception:144:24: note: definition of 'std::exception_ptr' is not complete until the closing '}'
class _LIBCPP_TYPE_VIS exception_ptr
                       ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/exception:149:5: error: '__abi_tag__' attribute only applies to structs, variables, functions, and namespaces
    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
    ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:689:37: note: expanded from macro '_LIBCPP_INLINE_VISIBILITY'
#  define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI
                                    ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:673:26: note: expanded from macro '_LIBCPP_HIDE_FROM_ABI'
          __attribute__((__abi_tag__(_LIBCPP_TOSTRING(_LIBCPP_VERSIONED_IDENTIFIER))))
                         ^
In file included from helloworld.cpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:41:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/ios:221:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:848:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/allocator.h:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/new:94:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/exception:149:55: error: expected ';' at end of declaration list
    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
                                                      ^
In file included from helloworld.cpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:41:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/ios:221:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:860:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/shared_ptr.h:28:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:173:32: error: member 'nullptr_t' declared as a template
  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(__value_init_tag(), __value_init_tag()) {}
                               ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:173:42: error: expected ';' at end of declaration list
  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(__value_init_tag(), __value_init_tag()) {}
                                         ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:262:25: error: unknown type name 'nullptr_t'
  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
                        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:395:32: error: member 'nullptr_t' declared as a template
  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(__value_init_tag(), __value_init_tag()) {}
                               ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:395:42: error: expected ';' at end of declaration list
  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(__value_init_tag(), __value_init_tag()) {}
                                         ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:484:25: error: unknown type name 'nullptr_t'
  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
                        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:533:14: error: unknown type name 'nullptr_t'
  void reset(nullptr_t = nullptr) _NOEXCEPT {
             ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:533:24: error: cannot initialize a parameter of type 'int' with an rvalue of type 'std::nullptr_t'
  void reset(nullptr_t = nullptr) _NOEXCEPT {
                       ^ ~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:533:24: note: passing argument to parameter here
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:594:45: error: unknown type name 'nullptr_t'
operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
                                            ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:602:12: error: unknown type name 'nullptr_t'
operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
           ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:610:45: error: unknown type name 'nullptr_t'
operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
                                            ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:618:12: error: unknown type name 'nullptr_t'
operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
           ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:626:44: error: unknown type name 'nullptr_t'
operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
                                           ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/unique_ptr.h:635:11: error: unknown type name 'nullptr_t'
operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
          ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.

I really have no idea how to fix this and have been trying for some time now. Can anyone give me some insight? I have uninstalled and reinstalled Xcode, I've tried g++ (doesn't work).

I tried uninstalling and reinstalling XCode.

*I have uninstalled and reinstalled Xcode* -- Are you sure you are running `clang++` with at least C++11 enabled? Your command-line does not specify the C++ language standard, and I don't know if C++98 is assumed, thus giving the error that `nullptr_t` is unknown. — PaulMcKenzie, Jul 29 '23 at 06:12
Apple clang defaults to a really old c++ standard. Try adding `-std=c++11` to your compile command line. You can use a higher standard if you like, c++14, c++17, c++20 but I believe `nullptr_t` is an 11 feature. You can also change this under the build settings for the project in xcode if you end up compiling there. — Retired Ninja, Jul 29 '23 at 06:13
[std::nullptr_t](https://en.cppreference.com/w/cpp/types/nullptr_t). Note that at least C++11 is required. — PaulMcKenzie, Jul 29 '23 at 06:14
I ran clang++ helloworld.cpp -std=c++11 and no luck. It spits out the same thing. Is there any way to do a complete uninstall and reinstall? It's strange, because when I use clang to run C code, it works just fine .. If I try using the same with g++ it gives me: ld: can't re-map file, errno=22 file '/usr/local/lib/libgcc_ext.10.5.dylib' for architecture x86_64 collect2: error: ld returned 1 exit status — GVB, Jul 29 '23 at 06:15
@GVB What is the version of `clang` you are running? `clang++ --version`, I would believe is the command-line. — PaulMcKenzie, Jul 29 '23 at 06:17
@GVB `` and `nullptr_t` are not part of C, so that's not strange at all. — john, Jul 29 '23 at 06:17
@PaulMcKenzie Apple clang version 14.0.3 (clang-1403.0.22.14.1) — GVB, Jul 29 '23 at 06:18
`can't re-map file` -- Give us the exact command-line you are using to compile using `g++`. — PaulMcKenzie, Jul 29 '23 at 06:23
With two different compilers not being able to run seamlessly, I would think you have a much more general problem with your system than compilers. [See this](https://stackoverflow.com/questions/13051163/ld-cant-map-file-errno-22-for-architecture-armv7) concerning the errno-22 error. — PaulMcKenzie, Jul 29 '23 at 06:32
Is there a solution here involving to sort of "reset" the compilers in a sense? I pretty lost :( — GVB, Jul 29 '23 at 06:34
@GVB This may be completely off, I'm no expert, but this error message `'/usr/local/lib/libgcc_ext.10.5.dylib' for architecture x86_64` mentions the x86_64 which is an Intel architecture, but AFAIK MacBook Air comes with Apple's M1 or M2 chip. So something seems to be wrong there. — john, Jul 29 '23 at 06:42
Im far from an expert here lol Im a mathematician who just happens to write code in C++ so all of these are quite out of my realm of expertise. I am wondering if there is a fix that is reasonably simple here. Otherwise, if worst case, would a complete factory reset of the computer do the trick? Some people from the Apple store moved all my stuff from my 2017 macbook to my new one. Not entirely sure what they did. — GVB, Jul 29 '23 at 06:47
Try running `xcode-select --install` in a terminal to make sure the command line tools are properly installed. That's for clang. For gcc you probably installed it with homebrew. I'd make sure all of that is up to date since you changed architecture. — Retired Ninja, Jul 29 '23 at 06:50
brew says everything is up to date and xcode says: xcode-select: error: command line tools are already installed, use "Software Update" in System Settings to install updates. Would it be worth bringing this to apple and having them look at it? — GVB, Jul 29 '23 at 07:00
Since you are using **brew**, did you happen to install GNU GCC (g++) or LLVM (clang++) through brew? What does `g++ --version` show? — Eljay, Jul 29 '23 at 13:26
As of now, I have an appointment scheduled at the Apple store tomorrow. I am hoping they can fix it. Worst case, I guess a back up of my data and factory reset will do the trick? — GVB, Jul 29 '23 at 15:25
@GVB -- If a simple `hello world` program doesn't compile, link, and run, it has to be the C++ compiler suite was not installed correctly for your computer. I am sure that C++ developers have used MacBooks to develop on. — PaulMcKenzie, Jul 30 '23 at 04:22

clang++ error: unknown type name 'nullptr_t'

0 Answers0