sunfora

C ^ C++

People often write C / C++ to denote they do not care which one of them to use.
But if we interpret it literally, it means the inverse of C++ interesected with C features.

Now. What C ^ C++ would look like?

1. Template and constexpr code
2. Asm (not in a C standard)
3. C specific things like restrict, allowed by c++ compilers as non-standard extension __restrict

In essense: it is a template ASM!

Here is a quick example (mostly AI generated):

template<int Count>
struct AsmLoop {
    static __attribute__((always_inline)) inline void unroll() {
        asm volatile(
            ".pushsection .rodata" "\n"
            ".L_cursed_str%=: .ascii \"C ^ C++ = asm\\n\"" "\n"
            ".popsection" "\n"
            
            "mov $1, %%rax" "\n"
            "mov $1, %%rdi" "\n"
            "lea .L_cursed_str%=(%%rip), %%rsi" "\n"
            "mov $14, %%rdx" "\n"
            "syscall"
            : : : "rax", "rdi", "rsi", "rdx", "rcx", "r11", "memory"
        );
        AsmLoop<Count - 1>::unroll();
    }
};

template<>
struct AsmLoop<0> {
    static __attribute__((always_inline)) inline void unroll() {}
};

template<int ExitCode>
[[noreturn]] void _start_template() {
    asm volatile(
        ".global _start \n"
        "_start:\n\t"
    );
    
    AsmLoop<3>::unroll();

    asm volatile(
        "mov $60, %%rax \n\t"
        "mov %0, %%rdi \n\t"
        "syscall \n\t"
        : : "i" (ExitCode) : "rax", "rdi", "rcx", "r11"
    );
    __builtin_unreachable(); 
}

template void _start_template<42>();