Can I make a bitwise copy of a C++ object?

Question

Can C++ objects be copied using bitwise copy? I mean using memcopy_s? Is there a scenario in which that can go wrong?

Answer 1

If it is a single object, why not use assignment operator (I suppose the compiler-generated assignment operator could be implemented in terms of memcpy if that is so advantageous, and the compiler knows better whether your class is a POD.)

If you want to copy an array of objects, you can use std::copy. Depending on the implementation, this may end up using memmove (one more thing that you can mess up - the buffers may overlap; I don't know whether the nonstandard memcpy_s somehow checks for that) if the involved types allow that. Again, the decision is done by the compiler, which will get it right even if the types are modified.