duplicate-argument

Flag the same parameter name declared more than once in a single signature. Julia rejects such a definition outright, so it is always a mistake. Positional and keyword parameters share one namespace.

x appears twice in the parameter list:

function dist(x, y, x)
    hypot(x, y)
end

example.jl:1:21: error[duplicate-argument] argument name `x` is used more than once