This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.
Boxed arrays cannot be allocated without initialization, because in that case the garbage collector would try to follow wild pointers. This is a source of inefficiency; quite a few operations must allocate a new array, initialize it, then overwrite the initial elements with the actually relevant data. This package provides low-level primitives for doing such operations without superfluous copying.
