alias = compile-time variants?

[Jason Spencer]

In writing templates that make heavy use of alias parameters, does
anyone else feel uneasy about whether the caller will pass a type, a
value, or a schmoo?  I'm having a hard time getting my head around
how wide-open aliases are and trying to resist the urge to put in
thousands of static asserts to check what should be invariants on
the kind of thing that can be passed in that position.  This all
feels very strange when I typically look for templates to provide
that nice, static, compile-time safety that keeps me from having to
check everything that gets passed.  Any words of wisdom on adjusting
to this feature?

Thanx,
Jason