As I integrated my Unicode library with Boost.StringAlgo, I noticed a few issues: - The Finder concept seems inappropriate, since find_iterator<last_finderF> can't work as expected. I suggest building left-to-right and right-to-left searching directly into the Finder concept. - Certain functions that take ranges only take Range& and not const Range&. Interestingly enough, in the cases where I've found it does that a const Range& would have been enough. - Usage of the Finder concept is incompatible with its definition. Indeed, finders are passed by const reference, which means the operator() must be const, unlike in the examples. - Finders are explicitly calling boost::as_literal on the string to search for, which I believe should not be their responsibility but that of the callee (or not, but I would have expected a rationale at least). - Why is there no trim variant that simply returns a sub range of the input range? There are only ways to modify the sequence in-place or copy a trimmed one. - Algorithms such as find being pushed in the boost namespace is incompatible with, for example, updated version of Boost.Range (Boost.RangeEx). Since boost::algorithm::find is quite different from std::find, it should not be promoted to boost::find. Since the library is fairly old (2002), I assume some of these issues are known. Is there any plan to fix them?