/**

@struct vrna_fc_s
@scripting
@parblock

This data structure is wrapped as an object @b fold_compound with several related functions attached as methods.

A new @b fold_compound can be obtained by calling one of its constructors:<br>
- @em fold_compound(seq) -- Initialize with a single sequence, or two concatenated sequences
  separated by an ampersand character '&' (for cofolding)
- @em fold_compound(aln) -- Initialize with a sequence alignment @em aln stored as a list
  of sequences (with gap characters)
.

The resulting object has a list of attached methods which in most cases directly correspond to
functions that mainly operate on the corresponding @em C data structure:<br>
- @em type() -- Get the type of the @em fold_compound (See #vrna_fc_type_e)
- @em length() -- Get the length of the sequence(s) or alignment stored within the @em fold_compound
.

@endparblock
*/
