SEAL is designed to be a simple and easy to use C++ library of common/day-to-day data structures and algorithms.
The C++ STL and the Boost libraries provide a rich set of data structures and algorithms which one can use in their day-to-day programming. However, having used both the Java API and the C++ STL/Boost, I am of the opinion that the STL/Boost do not provide an as neat and intuitive an API as the Java API. Moreover, learning to use STL/Boost is not as easy and comfortable as learning to use the Java API.
Keeping these drawbacks in mind, I have developed the SEAL C++ library as a simple, easy and lite alternative to the STL/Boost libraries. It tries to avoid the above mentioned negetives as much as possible, and incorporates the positives of the Java API as much as possible.