I have code like this:

template<size_t N>
std::string_view concatenateString(std::array<char, N> &buffer, std::string_view s1, std::string_view s2){
    // copy / concatenate string_view's into the buffer...
    // check for buffer overflow etc...

    return { buffer.data(), buffer.size() };
}

However, yesterday I forgot to pass buffer by reference:

std::string_view f(std::array<char, N> buffer, std::string_view s1, std::string_view s2){
                                   // ^ missing &
   return concatenateString(buffer, s1, s2);
}

Strangely enough because of the optimizer, code worked on some places and failed on other and I spent 15 min debugging it.

if std::array was custom type, I would be able to delete copy c-tor and operator=, so errors like this can not happen.

However in the way it is, I do not see how this can be done, unless std::array is wrapped in some other class, for example like this:

template<size_t N>
struct Buffer{
   std::array<char, N> a;
};

However this will make code ugly, unless I recreate most of the methods. Is much easier to create my own buffer class with raw array inside.

Another possibility would be to derive new class from std::array, which is even more ugly.

Do I miss any other possibility?