Re: buffer.c/buffer.h: How to add new buffer-local variables?

[Stefan Monnier]

> if (!NILP (BVAR (XBUFFER (w->contents), crosshairs))) ...

Buffer-local variables are appropriate in the `struct buffer` when it's
likely that most buffers will have their own setting for it.

For variables that are likely to be used only in some particular
buffers, or only under some particular circumstances, it can make a lot
more sense to declare them as global variables and then rely on the
Elisp side using `make-local-variable` or `make-variable-buffer-local`,
so you don't pay for that slot in every buffer even tho it's almost
never used.


        Stefan