The beauty and simplicity of the good old C-style void* in C++

Discussing several options, starting from the good old C-style void* pointer.

An interesting question you may ask in C++ is: “How would you declare a function that takes a blob of memory as input?”

For example, think of a function that hashes some input data (using SHA-256, or whatever hash algorithm), or a function that takes some binary data and writes that to disk.

Coming from my C background, an option that came to mind would certainly be:

void DoSomething(const void* p, size_t numBytes)

You simply pass a const void* pointer to the beginning of the input memory block, and the total size of the memory block, expressed in bytes.

Then, some C++ programmer could start complaining: “Hey, why do you use the unsafe old C-style void* pointer? Use some safe explicit type like uint8_t, which clearly represents an 8-bit byte!”.

So, they propose to “step up” to the following prototype:

void DoSomething(const uint8_t* p, size_t numBytes)

Now, suppose that you want to pass to this function a custom structure, like this:

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