80e3923b3c
C++20 introduced `contains` member functions for maps and sets for checking whether an element is present in the collection. Previously the code pattern looked like: <collection>.find(<element>) != <collection>.end() In C++20 the same can be expressed with: <collection>.contains(<element>) This is not only more concise but also expresses the intend of the code more clearly. This commit replaces all the occurences of the old pattern with the new approach. Tests: unit(dev) Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com> Message-Id: <f001bbc356224f0c38f06ee2a90fb60a6e8e1980.1597132302.git.piotr@scylladb.com>