C++ Const and Enum		    Bob Walton, 7/16/96


Data declared at top level (outside any function or
class declaration) may be declared to be const.  Such
data is implicitly declared to be static so that it will
be local to its translation unit: i.e. the .cc file
currently being compiled.  Thus

    int const i = 5;

is equivalent to:

    static int const i = 5;

Integer constants declared in this way and given values
that can be computed at compile time may be used in
expressions that declare the sizes of arrays, and in
other places where a compile time integer is required.

Because the `= 5' type of initializer is not permitted
for a class data member, const data members of classes
cannot be assigned values in this way, and cannot be
used as array dimensions.  Instead, enum constants must
be used, as in:

    class foo
    {
	enum { TABLE_SIZE = 101 };

	int table [ TABLE_SIZE ];

    };

    ...  foo::TABLE_SIZE ... 


Future versions of C++ may allow const int data members
to have initializers such as `= 5'.