Q:

std::copy equivalent in C

I have some code in C++ that use std::copy in these lines 
std::copy(array1, array1 + 4, arrayV + i);
std::copy(array2, array2 + 4, arrayV + i + 4);

inside a unroll loop. All of arrays are uint8_t*. 
How can I transform these lines for equivalent code in C that will produce the same result? 

A:

You can use memcpy:
instead of
std::copy(array2, array2 + 4, arrayV + i + 4);

you do 
memcpy(arrayV + i + 4, array2, sizeof(*array2) * 4);

If the memory blocks may overlap, you may use memove.

