Type this: class FooPrivate { void foo(); }; void FooPrivate::foo() { } Then go to ::foo() and make it ::foo(bool). Wait a long time (too long a time IMHO) and a fixit hint will appear suggesting "Update method signature". Ignore it, type space then 'b' (i.e. void FooPrivate::foo(bool b)). The fixit hint went away, and isn't coming back. Reproducible: Always Expected Results: It should offer me to update the method signature in order to insert "bool b".
Could you try again? This works & is reasonably fast for me. Update signature hint (yellow underline nowadays) pops up within a second. Using clipboardupdatertest.cpp from kio.git as test-case.