warning when returning a 'string'

[paciorek]

There's some issue with the returnType here. The code runs but emits the warning below.

nc <- nClass(
    Cpublic = list(
        run = nFunction(
            fun=function(mystr = 'string'){
                return(mystr)
            }, returnType = 'string'
        )))
cnc <- nCompile(nc)

Warning message:
Scalar type (string) for return() does not perfectly match the nFunction's return type (string).
 This occurred for: return(mystr)
 This was part of the call:  {
    return(mystr)
} 

I haven't investigated but would be happy to look into this at some point.