The implementation of the 'lib' rule. Beyond standard syntax that rule allows
    simplified: 'lib a b c ;'.

def lib(names, sources=[], requirements=[], default_build=[], usage_requirements=[]):
    """The implementation of the 'lib' rule. Beyond standard syntax that rule allows
    simplified: 'lib a b c ;'."""
    assert is_iterable_typed(names, basestring)
    assert is_iterable_typed(sources, basestring)
    assert is_iterable_typed(requirements, basestring)
    assert is_iterable_typed(default_build, basestring)
    assert is_iterable_typed(usage_requirements, basestring)
    if len(names) > 1:
        if any(r.startswith('<name>') for r in requirements):
            get_manager().errors()("When several names are given to the 'lib' rule\n" +
                                   "it is not allowed to specify the <name> feature.")

        if sources:
            get_manager().errors()("When several names are given to the 'lib' rule\n" +
                                   "it is not allowed to specify sources.")

    project = get_manager().projects().current()
    result = []

    for name in names:
        r = requirements[:]

        # Support " lib a ; " and " lib a b c ; " syntax.
        if not sources and not any(r.startswith("<name>") for r in requirements) \
           and not any(r.startswith("<file") for r in requirements):
            r.append("<name>" + name)

        result.append(targets.create_typed_metatarget(name, "LIB", sources,
                                                      r,
                                                      default_build,
                                                      usage_requirements))
    return result