CPLIB_GRAPH_GRIDTOGRAPH = 1

proc grid_to_graph(a: seq[seq[char]]; ok: char = '.';
                   return_static: static[bool] = false): auto

proc grid_to_graph(a: seq[string]; ok: char = '.';
                   return_static: static[bool] = false): auto

proc grid_to_graph[T](a: seq[seq[T]]; ok: T; return_static: static[bool] = false): auto

proc grid_to_graph_impl[T](a: seq[seq[T]]; ok: T;
                           return_static: static[bool] = false): auto