main.cpp

#include <stdio.h>
#include <iostream>
#include <memory>

typedef std::unique_ptr<int> Ptr;

int main()
{
    printf("Hello, world!\n");
    std::cout << "hey" << std::endl;
    return 0;
}

ok.txt

[nix-shell:~/Desktop/geos]$  aarch64-apple-ios-clang++ main.cpp
main.cpp:5:14: error: no template named 'unique_ptr' in namespace 'std'
typedef std::unique_ptr<int> Ptr;
        ~~~~~^
1 error generated.