On 03/18/08 17:23, Markus Werle wrote: [snip]
I am dreaming of:
scalar_field<0> rho; scalar_field<1> u; scalar_field<2> v; ....
Solver.AddPDESystem() [ddt(rho) + ddx(rho * u) + ddy(rho * v) + sourceterm == 0], [ddt(rho * u) + ddx(rho * pow<2, 1>(u)) + ddy(rho * u * v) == 0], [.. some other 10-20 partial differential eqns. omitted ];
[snip]
In chemistry there are systems with more than 100 equations of this form. One day proto will bend before such usecases. You've been warned ;-)
Spirit has something similar except it's equations always have a single variable (a.k.a. nonterminal in grammar parlance) on one side of the equation. For example, the calculator::definition CTOR here: http://www.boost.org/libs/spirit/example/fundamental/full_calc.cpp Spirit uses pointer's to the rhs stored in spirit::rule's which avoids, somewhat, the compiler limitations. Maybe you could do something similar. This sequence of grammar equations (a.k.a. productions) and a solution to these equations for non-terminal lookaheads is prototyped using proto in cfg_lookahead_extends.zip here: http://www.boost-consulting.com/vault/index.php?&directory=Strings%20-%20Text%20Processing However, instead of using '[]' to separate the equations, like spirit, this prototype uses ','. Maybe the lookahead prototype could give you some ideas for constructing the equations and solving them for your PDE solver.