LaurentGomila/SFML — comment on commit 191730ac0d639cfdef8fae560cdbc7d7e8c67db1
File: include/SFML/Graphics/Texture.hpp line 499
By LaurentGomila:

32-bit platforms have 64 bits integers too.

sf::Uint64, as its name implies, is *always* a 64-bits integer.