Casting byte array to multi-dimentional array

Question

I have a byte array serialized from a stream char* Buf which points to an array of 64 bytes.

I wish to cast it into a function input parameter Foo(char[4][16] Buf) without copying each and every single bytes.

Any easy for doing so?

You could pass it to the function if the underlying data structure is the same. That can be done because you can represent a 2D contiguous data structure as contiguous 1D array. If not you have to iterate through it by calculating the exact positions- — Andre Kampling, Jan 26 '20 at 06:59
Related: https://stackoverflow.com/questions/55593936/c-multidimensional-array-in-existing-memory — Michael Chourdakis, Jan 26 '20 at 07:18
If you received that data from a file or via network, copying the 64 bytes is not going to impact the performance of your program noticeably. — Ulrich Eckhardt, Jan 26 '20 at 07:54

score 0 · Answer 1 · answered Jan 26 '20 at 06:59

0

You can cast any buffer to any array you want:

void Foo(char(&buf)[4][16])
{
}

int main()
{
    char* buf = new char[64];
    Foo((char(&)[4][16])(buf));
    delete[] buf;
    return 0;
}

answered Jan 26 '20 at 06:59

Ali Asadpoor

2

Sure cast can be done, but if the underlying structure doesn't meet the expected one, it will not work as expected. – Andre Kampling Jan 26 '20 at 07:03

score 0 · Answer 2 · answered Jan 26 '20 at 08:06

0

I found the answer in link given by Michael Chourdakis

*reinterpret_cast<char(*)[4][16]>(Buf)

answered Jan 26 '20 at 08:06

s k

2 Answers2