There are many alternatives to Code::Blocks for Linux if you are looking for a replacement. The best Linux alternative is Eclipse, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Code::Blocks and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Code::Blocks are Apache NetBeans (Free, Open Source), Qt Creator (Free, Open Source), CLion (Paid) and CodeLite (Free, Open Source).
Ultimate++, also called U++, is a C++ cross-platform rapid application development framework focused on programmers productivity. It includes a set of libraries (GUI, SQL, etc..), and an integrated development environment.