C++ Math Constants

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This project collects various ideas about mathematical constants for C++.

Most of these constants are now in the standard for C++20. These versions under namespace emsr will work under C++17.

New ideas:

There are several directions this could go once the basics are in place.

• template<typename Constant, typename NumTp> class floating_point_constant { NumTp fact; };

• Constant is able to belch out mantissa bits - as many as needed for the type of float NumTp. Actually NumTp could be floating-point, rational or fixed-point.

• Math operations involving floating_point_constant would modify the factor and accumulate operations using template programming. Ratios need to cancel the constant.

• Only evaluate at the end and with the best precision.

• This could work a lot like units.