[igraph] casting to igraph_real_t

[Murat Tasan]

hi all - i just started using the igraph C library, and noticed that i
can't seem to find a function to reliably cast various C types to the
corresponding igraph_X_t type.
just as an example, i'm currently relying on what i've found in the
igraph_types.h to simply do things like:

extern double *edgelist; // declared/defined in an external library
that i can't control.
extern int edgelist_length;

igraph_vector_t v;

igraph_vector_view(&v, edgelist, edgelist_length);


... since igraph_real_t is defined as a double in igraph_types.h.

this doesn't seem quite safe to me, however, as if the igraph library
changes in the future quite a few things will break (in my code at
least).
i was somewhat expecting to find a series of casting functions, e.g.
as_igraph_real_t(int x), that would serve as a one-stop location for
moving between igraph types and standard C types, but if it does
exist, i can't seem to locate it.

do most folks here just use basic casting as the short code above, or
is there an accepted more uniform method?
such a series of casting functions would also make it easier to modify
a single module of code in the future in case the underlying types
change (rather than track down all the explicit and implicit casts
through the rest of all programs using the igraph library).

cheers,

-murat