Allow setting individual fields as 'unique' from the model Meta options

[Julien Phalip]

I'm dealing with this case:

class A(models.Model):
    blah = models.CharField(max_length=100)

    class Meta:
        abstract = True

class B(models.Model):
    pass

... where A is in a separate app than B and is used in multiple different contexts. I need to have the blah field be unique for B, whereas it shouldn't necessarily be unique in every other context where it is used. The only way I've found so far is:

class B(models.Model):
    pass

B._meta.get_field('blah')._unique = True # Ugliness alert!

Is it envisageable to allow setting the unique flag for individual fields from the Meta options, in the same way as with unique_together? Something like this for example:

class B(models.Model):

    class Meta:
        unique = ('blah',)