Question

I know the way of non meta programing to decide a PC is little endian or not.

eg:

#include <iostream>
#include <stdint.h>

union A { 
    uint16_t v;
    char c[2];
};  

int main(void) {
    A a;
    a.v = 0x0102;
    std::cout << (a.c[0] == 0x01 ? "big endian" : "little endian") << std::endl;

    return 0;
}

But, it’s expensive in run time, isn’t it?

So, is there a way to decide a PC is little endian or not by meta programing?

Thanks!

Answer 1

There’s nothing in the language that requires a target computer to be exclusively big-endian or exclusively little-endian. Indeed, some architectures allow endianness selection by the software at run time. Some even allow per-page endianness selection.

A template metaprogram cannot possibly know anything about this stuff.