103The comparability of different situations must be assessed with regard to all the elements which characterise them. These elements must in particular be determined and assessed in the light of the subject matter and purpose of the State measure which makes the distinction in question. The principles and objectives of the field to which the State measure relates must also be taken into account (see, by analogy, judgment of 12 May 2011, Luxembourg v Parliament and Council, C‑176/09, EU:C:2011:290, paragraph 32 and the case-law cited).