Why don't underscores in numbers enforce proper formatting?

[Adam D. Ruppe]

On Wednesday, 6 March 2013 at 21:06:43 UTC, ixid wrote:
> and not enforce digits to form sets of three after the first 
> underscore?

binary: 1000_1010
or binary: 11001001_11110000
hex: 10_10_40_ae
or hex: dead_beef


Decimal ones might do it too, because you can use a decimal 
literal for other things, like std.conv.octal. Which is a 
specific case where I don't think you'd split other than on 
three, it is still something I could imagine.