the effect inference for `collect_as` seems bad

[nsajko]

julia> using FixedSizeArrays

julia> Base.infer_effects(collect, Tuple{typeof((n*n for n ∈ 1:3))})
(!c,+e,!n,!t,+s,+m,!u,+o,+r)

julia> Base.infer_effects(FixedSizeArrays.collect_as, Tuple{Type{FixedSizeVector}, typeof((n*n for n ∈ 1:3))})
(!c,!e,!n,!t,!s,!m,!u,!o,!r)

julia> versioninfo()
Julia Version 1.12.0-DEV.1387
Commit 9f929892746 (2024-10-15 07:30 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × AMD Ryzen 3 5300U with Radeon Graphics
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, znver2)

[giordano]

Small improvements on e4d221a (notaskstate and :nonoverlayed are now inferred)

julia> Base.infer_effects(FixedSizeArrays.collect_as, Tuple{Type{FixedSizeVectorDefault}, typeof((n*n for n ∈ 1:3))})
(!c,!e,!n,!t,+s,!m,!u,+o,!r)

julia> versioninfo()
Julia Version 1.12.0-beta3
Commit faca79b503a (2025-05-12 06:47 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: macOS (arm64-apple-darwin24.0.0)
  CPU: 8 × Apple M1
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, apple-m1)
  GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 4 virtual cores)

Even better than collect if you hint the element type:

julia> Base.infer_effects(FixedSizeArrays.collect_as, Tuple{Type{FixedSizeVectorDefault{Int}}, typeof((n*n for n ∈ 1:3))})
(!c,+e,!n,!t,+s,+m,+u,+o,+r)

[nsajko]

Reproduces without FSA, moving to Collects.jl:

julia> using Collects

julia> Base.infer_effects(collect, Tuple{typeof((n*n for n ∈ 1:3))})
(!c,+e,!n,!t,+s,+m,!u,+o,+r)

julia> f(x) = collect_as(Vector, x)
f (generic function with 1 method)

julia> Base.infer_effects(f, Tuple{typeof((n*n for n ∈ 1:3))})
(!c,!e,!n,!t,+s,!m,+u,+o,!r)

EDIT: upstream issues:

• effect_free not inferred, unlike with Base.collect JuliaCollections/Collects.jl#33

• effect_free still not inferred for Memory JuliaCollections/Collects.jl#38