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replace constructorof with something not UB #99

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replace constructorof with something not UB #99

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8a4339e
replace constructorof with something not UB
vtjnash Mar 14, 2025
cf26ce7
Update ConstructionBase.jl
vtjnash Mar 14, 2025
1ecf0b2
Update ConstructionBase.jl
vtjnash Mar 14, 2025
0bf093c
Update ConstructionBase.jl
vtjnash Mar 14, 2025
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5 changes: 1 addition & 4 deletions src/ConstructionBase.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -26,10 +26,7 @@ for (name, path) in [
end
end

@generated function constructorof(::Type{T}) where T
getfield(parentmodule(T), nameof(T))
end

constructorof(T::Type) = Base.typename(T).wrapper
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Suggested change
constructorof(T::Type) = Base.typename(T).wrapper
constructorof(::Type{T}) where T = Base.typename(T).wrapper

Is there a reason why the where T was dropped as well?

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In practice, the where just reduces the information inference is permitted to use about the argument during inlining

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@rafaqz rafaqz Mar 15, 2025 •
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Ok, I guess I don't understand the scope of consequences of that.

From practical experience using where on types and functions like this often fixes type stability bugs.

(The reason for my concern is a small loss of type stability in constructorof could break the performance of 100s of packages)

constructorof(::Type{<:Tuple}) = tuple
constructorof(::Type{<:NamedTuple{names}}) where names =
NamedTupleConstructor{names}()
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