https://en.wikipedia.org/wiki/Residence_card_of_a_family_member_of_a_Union_citizen
Implementation in the United Kingdom
As of 6th April 2015, the non-EU family members of an EU national who are in possession of a residence card, which is issued to them under article 10 of directive 2004/38, are entitled to enter the UK without the need to apply for an EEA Family Permit, only by providing their residence card at the border. However, the UK border officers would grant entry to non-EU family members if they can prove their relation to the EU national family member who would be accompanying them, by providing documents such as marriage or birth certificate.
Does it mean, if I have a UK marriage certificate and EU spouse traveling with me, I can visit UK without visa ? (I'm Russian with Swedish permanent residency)