1 is not a UInt

New to Julia
1

Hi,

As typeof(1) == Int64, we have 1 isa UInt == false

However, this makes it difficult to pass a default value:

f(x::UInt = 1) = 2

f()
# MethodError: no method matching f(::Int64)

Sure, I can define:

f(x::UInt = UInt(1)) = 2

but it’s ugly…

DD

2

It would be a really bad idea for 1 to default to UInt :scream:

I would not expect this to change. Otherwise 1 - 3 would be type unstable or have integer underflow.

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3

There is a literal syntax for UInt64, but it is more verbose than typing UInt(1):

julia> 0x0000000000000001 == UInt(1)
true
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4

True…
But the issue here is handling of default parameters.
Why not automatically convert those? They are constants, so this can be done at compile time.

5

Yeah, open an issue for conversion of literals in defaults. That would be a little magical, but that could happen in that specific context (reminiscent of literal_pow). But the general topic here, 1 is not a UInt, I think is a done deal.

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6

This was already discussed. See: dispatch behavior of optional arguments · Issue #7357 · JuliaLang/julia · GitHub

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