multiprecision

I've read from the boost::multiprecision documentation : Depending upon the number type, precision may be arbitrarily large (limited only by available memory), fixed at compile time (for example 50 or 100 decimal digits), or a variable controlled at run-time by member functions. The types are expression-template-enabled for better performance than naive user-defined types. I've read some more documentation but I've not found anything regarding changing precision at runtime. I've seen only templates that allows me to set precision at compile time, that's not what I want (I want to create a

Do you know how to do this simple line of code without error using Boost::multiprecison ? boost::multiprecision::cpp_int v, uMax, candidate; //... v += 6 * ceil((sqrt(uMax * uMax - candidate) - v) / 6); Using MSVC there is an error for "sqrt" and it's possible to fix it with: v += 6 * ceil((sqrt(static_cast<boost::multiprecision::cpp_int>(uMax * uMax - candidate)) - v) / 6); Then there is an error for "ceil" and it's possible to fix it with: namespace bmp = boost::multiprecision; typedef bmp::number<bmp::cpp_dec_float<0>> float_bmp; v += 6 * ceil(static_cast<float_bmp>((sqrt(static_cast<bmp:

I am trying to write a program for finding mersenne prime numbers. Using the unsigned long long type I was able to determine the value of the 9th mersenne prime, which is (2^61)-1. For larger values I would need a data type that could store integer values greater than 2^64. Please help. (I should be able to use operators like , =,>,< and % with this data type.) You can not do what you want with C natives types, however there are libraries that let handle arbitrarily large numbers, like the GNU Multiple Precision Arithmetic Library . To store large numbers, there are many choices, which are