Java or C++ equivalents to Preon?

Preon is a Java library meant for creating binary codecs: you simply place annotations in a class' data members regarding their correspondence with bit fields (e.g. number of bits to use for certain field) and, based on such class, the library builds a Codec object that is able to create instances of the class reading their data from a binary input开发者_如何学C stream.

Due to licensing issues (it is distributed under GPL), I cannot use it.

Are there any libraries with equivalent or similar functionality, either in Java or in C++?

looking at the license page, the preon library is "GNU General Public License, version 2, with the Classpath Exception", which is important. that allows you to use the library in binary form without your application also being GPL.

Take a look at Java Binary Block Parser library, it allows to make bit field parsing and mapping to class fields