Could the usage of `haskey` be unidiomatic/inefficient?

General Usage Performance
3

What about

function dostuff(dict, key)
    found = true
    item = get(() -> found = false, dict, key)
    if found
        Some(item)
    else
        nothing
    end
end

d = Dict([1 => 'a'])
dostuff(d, 1)                   # Some('a')
dostuff(d, 2)                   # nothing