Trying to get a better handle on the `char buff` vs `std::vector<char>` issue.

Both Clang and GCC (the two compilers SFML uses on Mac) support variable-length arrays for compatibility with C99. This is a Mac-specific implementation file so we know this feature will be supported.

Is the issue that it's not a _C++_ standard feature but rather a _C_ one? When working with a platform-specific implementation how do you decide whether to take advantage of a feature provided by that platform or to stick to standards? I assume "always favor standards", but I'd like to hear your thinking.

To be clear, I'm not questioning whether this change is good (it's almost certainly better than what I have), I'm just trying to understand the thinking behind it clearly.