[Fresco-devel] Suggested addition to Coding Style-guide

----
When using a class name in a function declaration such as:

  void do_foo(some_type &x);
  int  do_bar(type_space::nested_type *y);

it is often not necessary to include the entire header file in which the
types are declared. Instead it is preferable, to reduce build-time
dependencies, to use:

  void do_foo(class some_type &x);

or if some_type is used multiple times within the same file (or the
class is within a namespace), to predeclare:

  class some_type;
  namespace type_space
  {
    class some_type;
  };
  /* ... */
  void do_foo(some_type &x);
  void do_bar(type_space::nested_type *y)
----

In quite a few instances (if not a *lot*!) we don't currently do this;
it seems like a good common idea, so assuming no discussion to the
contrary it'd be good to add it to the coding guide. Oh, and implement
it ;)

Comments?

-- 
Neil