[Insight-developers] Re: Borland C++ compiler and enums

[Brad King]

Hi Jim,

>   enum { SpaceDimension      = NDimensions,
>              ParametersDimension = NDimensions };
[snip]
> Does anyone know a work around for this problem?

We can use a static const int instead of an enum on some platforms.  In
fact, I have now come to the conclusion that a static const int is the
CORRECT choice, and that an enum should be used as a workaround.

Standard C++ allows in-class static member initialization for const
integral types:

struct Foo
{
  static const int bar = 1;
};

Most compilers support this, but those that don't seem to support the enum
as we are currently using.  The boost libraries use a macro like this:

struct Foo
{
  ITK_STATIC_CONSTANT(int, bar = 1);
};

On conforming compilers, the macro is defined like this:
#define ITK_STATIC_CONSTANT(type, assignment) static const type assignment

on other compilers, it is defined like this:
#define ITK_STATIC_CONSTANT(type, assignment) enum { assignment }

This should allow transparent usage of the constants for most purposes.

-Brad