simplify if condition
always initialize variable
directly initialize variables
remove dead code
reduce variable scope, remove dead comments
remove declared, but unimplemented function remove unused global variable
removed unused member, removed member which was only ever read, never written
remove unnecessary forward declaration
remove declaration of struct that is defined below
remove redundant cast convert malloc + memset to calloc
use bool literals (clang-tidy)
use nullptr instead of 0 (clang-tidy)