Re: C++ question on wrapper API for setting Guile fluids

[Dan Eble]

On Apr 22, 2022, at 05:39, Jean Abou Samra <jean@abou-samra.fr> wrote:
> 
> You both made a good point. My conclusion is that I should stick to
> 
>   {
>     Local_assumption la (Lily::prebreak_estimate, SCM_BOOL_T);
>     ...
>   }
> 
> where the constructor does everything, included scm_dynwind_begin ()
> and scm_dynwind_fluid (). That's safer and clearer, and never mind that
> you have to construct 3 contexts if you need 3 assumptions. I expect
> this to be very rare anyway.

Fine.  At the time someone wants more than one assumption, we might be able to 
add

    Local_assumptions la {{fluid1, value1},
                    ^     {fluid2, value2} /* etc. */ };

where the constructor accepts std::initializer_list<std::pair<Fluid, SCM>> but 
I don't know if there are any problems related to GC (and I'm not planning to 
work through that now).
— 
Dan