JuliaLang/julia — pull request #8759 by jiahao (2014-10-22 00:33:58+00:00)
Title: Add support for zero(::Array{Array})

The problem with the existing definition is that it tries to call zero(::Type{Array}), which fails because it doesn't know what size the eltype should be.

The solution here is simple - if the outer Array is not empty, call zero on its first element.

A similar problem occurs with one() but that is harder to fix.