Is there any way to use a “constant” as hash key in Perl?

Question

Is there any way to use a constant as a hash key?

For example:

use constant X => 1;

my %x = (X => \'X\');

The above code will cr

Answer 1

One way is to encapsulate X as (X):

my %x ( (X) => 1 );

Another option is to do away with '=>' and use ',' instead:

my %x ( X, 1 );