On Julia 1.0.2 julia> Float64 <: Real true as it should be but julia> Complex{Float64} <: Complex{Real} false Mathematically speaking, this should be true as well but, I guess, Julia has to deal with types of a more general nature, which probably makes it difficult to determine whether one compo…

You need Complex{<:Real}. That’s due to type invariance, while what you want is covariance (look for these keywords in the manual).

I have wondered why Julia has this limitation. Is it for performance or just to reduce complexity?

It’s not a limitation, its a property. It’s deeply related to everything in the language and basically everything has to be done differently if you change this so it’s hard to say what exactly it is for. Of course someone might be able to comment on the original reason this is selected, though find…

Thanks a bunch! It looks like, indeed, I needed type covariance all the way and just coincidentally didn’t run into the same problem before. The funny part is I did read that part in the manual and it made sense but somehow syntactic details didn’t register.

[image] xiaodai: I have wondered why Julia has this limitation. Is it for performance or just to reduce complexity? It’s absolutely critical for performance, as I explained in another post.

Complex{Float64} <: Complex{Real} is false. Intended or potential inconsistency?

General Usage

stevengj November 25, 2018, 12:45am 6

It’s absolutely critical for performance, as I explained in another post.

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Complex{Float64} <: Complex{Real} is false. Intended or potential inconsistency?

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