Collection extend [
    totalsize [
        ^self inject: 0 into: [:x :y | (y isKindOf: Collection) ifTrue: [x + y totalsize] ifFalse: [x + 1]]
    ]
].

a := #(2.7 #( ) #(3.1 #(4 #( #(true #( )) $c #( #(5)) $x)) #( )) false).
a totalsize printNl.
s := Set new.
s add: #(2.7 3.1) ; add: 4 ; add: #(true $c 5) ; add: #( ) ; add: #($x) ; add: #( #(false) ) .
s totalsize printNl.