* ncplane_at_* and ncplane_at_cursor_*
We had notcurses_at_yx() expanding into three distinct parts of
the cell structure, and ncplane_at_yx() / ncplane_at_cursor()
writing directly to a cell. It was annoying to remember which
was which. The latter two now have a signature matching
notcurses_at_yx(), while the old functionality has been moved
to ncplane_at_yx_cell() and ncplane_at_cursor_yx(). #476
We do proactive reallocations of the EGCPool once we get
to 90% capacity, to avoid expensive exhaustive searches. When
we're over half the maximum size, though, this will fail. We
shouldn't treat that as a hard failure, but instead proceed on
to the search. This lets us hit the full 32MB EGCPool size #486.
Nick prefers error handling based on exceptions in all cases, while I
prefer to save exception handling for truly exceptional situations -
function parameter validation and class constructor. However, there's no
need to not support both approaches, to be chosen at the discretion of
the developer.
NCPP follows RAII and all classes throw exceptions from their
constructors in case they cannot initialize properly. Likewise,
functions taking pointers that are required validate them and throw
exceptions whenever the requirement isn't met.
This commit goes one step further in that it enables optional validation
of notcurses function return values and throwing an
exception (`ncpp::call_error`) should the function signal an error. This
is disabled by default but it can be enabled by defining the
`NCPP_EXCEPTIONS_PLEASE` macro (preferably on the command line or
before *each* inclusion of any NCPP headers).
Out of necessity, this breaks the ABI (plus I found a handful of minor
issues in the code), but I think it's worth having this support in
place.
