https://issues.dlang.org/show_bug.cgi?id=14037
sinkuup...@gmail.com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |sinkuup...@gmail.com Hardware|x86 |All OS|Windows |All --- Comment #1 from sinkuup...@gmail.com --- Error on assigning to AA of BigInt seems a compiler problem: https://issues.dlang.org/show_bug.cgi?id=14089 However, memoize shouldn't assume that an overloaded opAssign returns the object. So I think your fix to memoize is necessary. --