For performance code, avoid std::copy at all costs, especially if you’re really using it to perform a memcpy.
Everyone at NVIDIA likes to think that their code is performance-sensitive. Nobody answers yes to the question "do you like to write slow programs?" Yet in the wider body of programmers (incl. our own) virtually nobody can tell a-priori what is slow or fast, in spite of the mass delusion that we can.
What we have above is a very valuable meme that I just wish you would not remember as "std::copy is for people who like it slow". Memes like this one are useful pieces of programmer wisdom to put into your book of tricks, but the daily application of such memes alone enables maybe 1% of programmers to write fast code by accident. While this way of working best shows off one’s elite status, it’s completely inappropriate.
When it comes to writing performance-sensitive code, there’s only one golden rule to ensure success:
If you’re writing performance-sensitive code, use a profiler. Early. Often.
I hope you found value in this.