I'm looking for an arbitrary precision floating point library for C/C++ (plain C is preferred). I need arbitrary precision exponents. GMP and MPFR use fixed size exponents, so they are ineligible (I have some ideas for workarounds, but I prefer an out-of-the-box solution). It would be an nice feature if the exponent precision can be adjusted automatically to prevent infinity-values.
If you know for sure that such an library does not exist, please say so.