I don't understand how to use the STL in C++

You seem to me to be saying that you don't understand the standard library. It is VERY logical, VERY well designed and something you will need to understand if you want to write efficient C++ code. I'd suggest you buy a good STL book and work through it, along the way you'll learn some basic computer science concepts that will help you enormously, even if you choose to write your own containers and not harness the power of STL.

Ok. i accept your ideal. But i want more the libraries you think they are good.

ok. i will research STL more.
thank all you.
and now. i have read code in stl_vector.h but i can't understand it.
anybody in here can help explain code in stl such as stl_vector.h

As others said STL is so important if you are developing on C++. If you don't understand STL, you are not using C++.

STL code is complicated because it is expected to support a wide range of compilers while maintaining the generic nature. It uses templates heavily which can be confusing for beginners. I'd suggest you to learn template meta programming first before you take a look at STL code. Learning that will make many things in the STL code more clear to you.

Also don't look at the Microsoft's implementation of STL. Read the code which GCC has got. In that, vector.h is a facade header file and the real implementation is on stl_vector.h. On a LINUX machine it will be in /usr/include/c++/gcc_version/vector.h and /usr/include/c++/gcc_version/bits/stl_vector.h.

To understand the logic of how it works, the source may not be the good starting point:

1. Because it is oftem "obfucated" by a number of preprocessing definition to adapt the source itself on different usage for different compilers and environment
2. Because the order that makes things appear in the source is often due to the language syntax needs, than to the importance of the things in the context.

You will probably more successful in google "STL tutorials" and than (after you understant STL usage) try to look the sources.

A good starting may be this one:
http://www.cs.brown.edu/~jak/proglang/cpp/stltut/tut.html[^]

Strange answers for a far from being stupid question ...
Actually this guy has good companions:

Just look here:
(Alexandrescu opinion)[^]

It explain why iterators may be considered far from ideal, but doing so, it also explain how they work.

Unortunatly, the STL is what the today C++ allows to define.
Future releases may be will be different.

Moral: don't "escape" the STL, understand it and find a bette rway to enhaence it!