c++ - Xcode: fatal error: 'iostream' file not found

Question

OS: macOS Big Sur Version 11.1 Xcode: Version 12.3

I haven't run C++ on my Mac in 8 months or so. I am trying to run a simple helloworld.cpp file:

#include <iostream>
using namespace std;


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

    return 0;
}

When I run cpp helloworld.cpp in my terminal I receive:

helloworld.cpp:1:10: fatal error: 'iostream' file not found

And when I run clang++ -v helloworld.cpp, it says (followed by a long error):

InstalledDir: /Library/Developer/CommandLineTools/usr/bin

I think the InstalledDir path is the problem based on other posts I've seen. When I run the code in Xcode or CLion it works fine. I looked at this tutorial on YouTube that changes the path to:

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/

However, I am confused as to how to change this path for the InstalledDir (assuming that's the issue) so that it works in terminal, not just inside of Xcode.

Update: I also just tried using xcode-select --switch /Applications/Xcode.app/Contents/Developer/ to change the path from /Library/Developer/CommandLineTools/usr/bin and I am still receiving the error.

The error:

In file included from helloworld.cpp:1:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/iostream:37:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/ios:215:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__locale:14:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string:504:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string_view:175:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__string:57:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/algorithm:642:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/utility:204:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdint:144:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:
In file included from /usr/local/include/stdint.h:59:

Answer 1

You should not have an stdint.h in /usr/local/include. Where did that file come from?