2011/12/7 Paul A. Bristow <pbristow@hetp.u-net.com>
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).
I like this ;-)
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?
I'm not sure if these are important constants, but if there are: root_three, half_root_two, one_div_root_two, then I'd add: half_root_three, and one_dif_root_three.
2 Please tell me of mistakes and typos in the draft docs.
Regards Kris