According to the v0.5 docs, `ccall(..., (Ptr{BigFloat},..), &aBigFloat, ..)` is deprecated in favor of `ccall(..., (Ref{BigFloat},..), aBigFloat, ..)`. It seems that using `Ptr{Type}` needs to be paired with `&varOfType` using the ampersand. When would one use `Ptr{Type}`?
- [julia-users] in ccall when to use Ptr{} rather than Ref{}... Jeffrey Sarnoff