Syntax for restricted width string types

[Henrik Grubbstr�m (Lysator) @ Pike (-) developers forum]

I'm considering adding support for differentiating between different
width strings to the type system. This whould be useful in tracking
down places where wide strings are passed where narrow strings are
expected. The question is what the syntax should be. Please note that
the syntax should aim at being 100% backward compatible, so adding new
keywords is probably not a good idea.

My suggestion:

  string(8)     8-bit (aka narrow)
  string(16)    At most 16-bit wide
  string(32)    At most 32-bit wide (default)

This would allow for the possible extension of

  string(7)     7-bit (aka USASCII)

Comments?