Don't initialize CoordinateSequence in constructor

[eyal0]

This ought to improve performance in the common case where initialization is unnecessary.

This fixes #764

[eyal0]

@dbaston Please take a look, thanks.

[pramsey]

@dbaston, is this a go or a no?

[dbaston]

It makes me nervous despite seeing the tests pass. I would rather creation sites clearly indicate that they do not require initialization by using the constructor that provides this parameter.

[eyal0]

Does such a constructor exist?

I'm trying to remember why I found this issue in the first place. I suppose some unit test of mine found it. Maybe performance tanked or something?

[dbaston]

Yes, see

geos/include/geos/geom/CoordinateSequence.h

Lines 85 to 96 in 4c3bd72

	/**
	* Create a CoordinateSequence that packs coordinates of any dimension.
	* Code using a CoordinateSequence constructed in this way must not
	* attempt to access references to coordinates with dimensions that
	* are not actually stored in the sequence.
	*
	* @param size size of the sequence to create
	* @param hasz true if the stored
	* @param hasm
	* @param initialize
	*/
	CoordinateSequence(std::size_t size, bool hasz, bool hasm, bool initialize = true);

[robe2]

This has been sitting here for over a year are we thinking about doing anything about it @dbaston @eyal0 @pramsey

[pramsey]

Like @dbaston I hate mucking around in the initializers, because the knock-on effects are subtle. I defer to him as usual.