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Coding Standards
boost::log::expressions::wrap_filter
// In header: <boost/log/expressions/predicates/wrap_filter.hpp> template<typename FunT> unspecified wrap_filter(FunT && fun);
The function wraps a function object in order it to be able to participate in filtering expressions. The wrapped function must be compatible with the following signature:
bool (attribute_value_set const& values) const
The wrapped function must return true if the log record is to be passed by the filter and false otherwise.