Reference to the value of a named function argument

Within a function body I’d like to refer to a value of a named argument.
An example of what I have in mind, how to implement f:

function f(; arg1, arg2, argname)
    println("value of argument named $argname is: ???")

so that it’s invocation produces:

julia> f(arg1 = 1, arg2 = "b", argname = "arg1")

value of argument named arg1 is: 1

I am not sure I understood your question. $argname already prints the value of argname.

So to print your sentence you can use just:

 println("value of arg1 is: $arg1")

I am after the value of the argument named by argname.

In my example the output should be “b” if the value of argname is arg2

I amended the example to make this more clear.

Not really sure what you want or why. I suspect there’s a better way of doing what you really want.
But this might be what you asking about directly?

function f(; kwargs...)
    arg = Symbol(kwargs[:argname])
    println("value of argument named ", arg, " is ", kwargs[arg])

f(arg1 = 1, arg2 = "b", argname = "arg1")
f(arg1 = 1, arg2 = "b", argname = "arg2")