uint64_t 数组和 uint8_t 数组之间的 cpp 标准样式转换

Question

I'm looking for a cpp "std-style" way to access an the same static array as uint64_t array and uint8_t array, here are examples how I saw it solved in C, without bit operations:

union {
    uint64_t u64[16];
    uint8_t u8[128];
} array;

// array.u8[13];

or,

uint64_t u64_array[16];
uint8_t* u8_array = u64_array;
// u8_array[13];

Answer 1

There really only is the way of casting to a pointer to one of the many char types. If you want to mix in some std ishness how about this:

uint64_t u64_array[16];
auto raw = std::span{(uint8_t*)u64_array, 128};