This really seems like a bug to me, but perhaps I’m missing some kind of obscure difference between (x, y) and x => y syntax… import Base: ==, big import IntervalArithmetic: Interval struct Foo <: Real v end # Necessary for printing ==(x::Foo, y::Float64) = x.v == y big(x::Foo) = big(x.v) # Th…

Btw, the error message is ERROR: LoadError: MethodError: no method matching atomic(::Type{Interval{Foo}}, ::Interval{Foo}) Closest candidates are: atomic(::Type{Interval{T}}, ::Interval) where T<:AbstractFloat at /Users/skainswo/.julia/packages/IntervalArithmetic/UR6Qe/src/intervals/conversion.jl…

[image] Samuel_Ainsworth: but perhaps I’m missing some kind of obscure difference between (x, y) and x => y syntax They do different things, so I’m not sure why you expect to behave the same. The difference is that a tuple just takes the two values as they are, in the stacktrace of the Pair …

At the risk of getting sidetracked, why does Julia have redundant Pair and tuple constructs? [image] giordano: The difference is that a tuple just takes the two values as they are, in the stacktrace of the Pair constructor you can see convert(::Type{Interval{Foo}}, x::Interval{Foo}) is called, …

[image] Samuel_Ainsworth: But why doesn’t it just call the convert implementation here Yeah, that does seem odd. I don’t quite understand what’s happening. You might have to file an issue at the IntervalArithmetic.jl repo.

[image] Samuel_Ainsworth: At the risk of getting sidetracked, why does Julia have redundant Pair and tuple constructs? See `Pair{A,B}` vs. `Tuple{A,B}` - #5 by Tamas_Papp and links therein.

[image] Samuel_Ainsworth: At the risk of getting sidetracked, why does Julia have redundant Pair and tuple constructs? Redundant? They have different semantics: tuple is a container of arbitrary size, Pair is only for, well, pairs of the type key => value. [image] Samuel_Ainsworth: But …

I’ve opened What is required to use custom types in `Interval`s? · Issue #476 · JuliaIntervals/IntervalArithmetic.jl · GitHub

[image] giordano: Redundant? They have different semantics: tuple is a container of arbitrary size, Pair is only for, well, pairs of the type key => value. I’m not aware of any other languages that make this distinction. In most languages I’ve experienced tuple is explicitly not a container o…

Ha, I think he meant that you can make a tuple of any size, not that you can change the size of an existing tuple. :slight_smile:

Ah I see… But then I’m not sure why the distinction with Pair…

`(x, y)` works but `x => y` doesn't

General Usage

Jeff_Emanuel June 10, 2021, 11:05pm 6

See `Pair{A,B}` vs. `Tuple{A,B}` - #5 by Tamas_Papp and links therein.

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`(x, y)` works but `x => y` doesn't

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