I'm developing code libraries for use in web projects. Its important that the code be memory effecient, but there is no way to track this currently.

The way php handles objects and arrays it's hard to know when copies are being made internally. As I understand it, if you have $a=$b in your script, if $b is an object or array, its not actually copied. Only if there was a change in one of the elements through $a, does the the object get copied and the change applied on the copy.

So it would be very useful to have a function that reports on the internal memory allocations being made by a script, so we one can track if excessive copying is being made.

Just returning the size would be good enough. Being able to get it in categories (ie. resources, arrays, objects, references) would be fantastic.