While you have automatic code completion, requesting it manually is often a very good idea. Press Ctrl + Space and you'll get a detailed code completion list. Navigate with the arrow buttons (Up/Down) and press (and keep pressed) Alt to show documentation of the focused item. Press Enter to insert the item.
Assume you have something similar to this:
#include <vector> void myFunc(const std::vector<int>& v) { }
Now you want to iterate over the contents, instead of writing the type of the iterator, you just write:
it = vector.begin();
Now wait a second until the assistant pops up at the bottom of the editor. Press Alt + 1 to execute the assistant and you end up with:
std::vector< int >::iterator it = v.begin();
Nice, lots of time saved. 
And this should work with most/all expressions, as long as the right side can be evaluated, you should get an assistant that adds the correct type to the left side.
Example code:
class foo { int bar(); }; int foo::bar() { }
Now try the following things and after each step wait shortly and apply the assistant that pops up at the bottom of the editor with Alt + 1:
KDE UserBase Wiki 
• 
• int foo to either signature in the definition or the declaration.
const
Again, a very handy time saver!
Example Code:
class foo { int bar(); }; foo::bar() { }
Now write this into the implementation of bar:
myVar = 1;
You should get an assistant that offers you three options:
int myVar (see type assistant above)
int myVar, adds the declaration to the class body
int myVar, same as above, but in private section.
This even works for functions:
class foo { }; int main() { foo f; }
Now write this below foo f;:
f.someFunction(1, true, "asdf");
The assistant now offers you to declare that function, you'll end up with:
class foo { public: void someFunction( int arg1, bool arg2, const char* arg3 ); };
Cool .
Example code:
class A { public: virtual A* foo(int something){} }; class B : public A { };
Inside the class body of B press Ctrl + Space to bring up code completion. You should notice an item to overload foo(int something);. Execute it with Enter and you should get:
class B : public A { public: virtual A* foo(int something); };
Cool .
Continue where we left of in the Overload Helper:
class B : public A { public: virtual A* foo(int something); };
Place your cursor below the class context, request code completion with Ctrl + Space, you should notice an item to implement B::foo(int something);. Execute it with Enter and you should get:
A* B::foo(int something) { A::foo(something); }
Awesome .
is probably one of the features in KDevelop that increases productivity:
Press Ctrl + Alt + O and type part of a filepath, press Enter and the selected file gets opened. The search is separated by forward slashes, i.e. you can write this: /a/.cpp and the list will only show paths that have a folder starting with a and files that end on .cpp. Try it out.
Ctrl + Alt + C and input (parts) of the qualified class identifier, press Return and jump to the declaration of that class.
Also make sure to explore the other advanced features in .
Similar to quick open, pressing Ctrl + Alt + N gives you an outline of the current document with the ability to search for an identifier and quickly jump to its declaration.
Hover a use, declaration or definition and you'll get a popup with information about it. You can also move your cursor in there and press (and keep pressed) the Alt button to show that popup without using the mouse. Use the arrow keys to navigate between the links in the popup, use Enter to jump to the destination of a link.
When inside a use, press Meta + Left or Meta + Right to jump to the previous/next use. Press Ctrl + . or Ctrl + , to jump to the declaration or definition of the symbol under the cursor. Alternatively click on a symbol with Ctrl button pressed to do the same.
Also take a look at the menu and it's various shortcuts. Context browsing is awesome!
KDevelop 4 does not support very well the autotools. I suggest using Konsole to run configure scripts to build makefile. The custom makefile support works quite well. I suggest using separate building folder (say project/build).
After the custom makefiles are in place (say in build-directory) one can add that to build list by clicking the 
button on lower left corner Project selection while build directory is selected. This causes command make to be run when pressing . One can also directly run say make install on specific directory by right clicking the folder and selecting make install. This is nice if you have lots of projects in working set.
Libtool also causes problems if you try to debug application that has been linked with libtool: the program that you see in for example src/bin/program is not the executable, but a script that handles the libraries.
Problem is properly solved in console by runninglibtool --mode=execute <dst_binary>but at least currently KDevelop4 does not work good (at all) with other console than default. I have been stuck of using the real binary (found usually from src/bin/.libs/<exec>) that might use wrong libraries, so do make install before every run.
Using the Qt Documentation plugin you may integrate KDE documentation along with Qt documentation. Point your browser at KDE API Reference and download the desired .qch file (not all modules provide one). Then configure the Qt Documentation plugin by adding the downloaded files. That's it! Whenever you hover a KDE class you can see a link which points to KFooClass documentation. Enjoy.
