Boost.Math has always had an inconspicuous collection of useful math constants, mainly those that are used internally. The presentation of these was as a function-template, called for example, as pi<double>(). using namespace boost::math::constants; return pi<Real>() * r * r; This leads to some rather ugly equations and is most unpopular with scientific and engineering users. John Maddock has now added a new cunning feature that allows the vast majority of users who just want a built-in double to get the constants quickly as plain variables. So in non-template code, users can write using boost::math::double_constants; double area = pi * r * r; and users can read the equations easily. (Float and long double are similarly available in their own namespaces). The original mechanism which can be used for higher multiprecision user-defined floating-point types appears unchanged but has been improved to work better with UDTs and high precision types. Some draft detailed docs about just these new proposals are at http://boost-sandbox.sourceforge.net/libs/math_constants/doc/html/index.html We would like to be sure that 1 This additional mechanism of presenting constants is acceptable. 2 It is acceptable to add more constants (current new list is about 60 constants). Are there important constants that you think we have missed? Do we need a mini-review? Other views? Paul PS 1 Are there important constants that you think we have missed? 2 Please tell me of mistakes and typos in the draft docs. --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow@hetp.u-net.com