Note
KDevelop doesn't always know when to assist you in completing code. If the auto-completion tooltip doesn't automatically open, hit Ctrl + Space to open a list of completions manually. In general, in order for auto-completion to work, KDevelop needs to parse your source files. This happens in the background for all files that are part of the projects of the current session after you start KDevelop, as well as while after you stop typing for a fraction of a second (the delay can be configured).