should @view work for strings?

[stevengj]

Is there some reason why @view and @views don't produce SubString objects?

julia> s = "αβγ"
"αβγ"

julia> s[3:5] # a copy
"βγ"

julia> @view s[3:5]
ERROR: MethodError: no method matching view(::String, ::UnitRange{Int64})
Closest candidates are:
  view(::AbstractUnitRange, ::AbstractUnitRange{var"#s91"} where var"#s91"<:Integer) at subarray.jl:167
  view(::StepRange, ::AbstractRange{var"#s91"} where var"#s91"<:Integer) at subarray.jl:175
  view(::StepRangeLen, ::OrdinalRange{var"#s91",S} where S where var"#s91"<:Integer) at subarray.jl:179
  ...
Stacktrace:
 [1] top-level scope at REPL[25]:1

julia> SubString(s, 3:5) # I wish this was @view s[3:5]
"βγ"

julia> @views s[3:5]  # actually returns a copy
"βγ"

julia> typeof(ans)
String

Fixing @view would be a non-breaking change since it currently throws an error. Fixing @views would technically be breaking but I'm skeptical that it affects any real code?

[simeonschaub]

Does this not already work on nightly? (Ref #35879)

[stevengj]

Oh, great! Yes, it is fixed on nightly, I totally forgot about that PR!