assert and static assert and code generation

[Cecil Ward]

The compilers should surely be able to use the presence of static 
asserts to enable better code generation since the direction of 
some later conditional branches can be known, value ranges can be 
known, all kinds of potential good stuff. Is that correct?

If assert without the static is implemented as debug assert then 
unless the compiler makes an exception and does not all the 
‘debug’-conditional to simply wipe out the assert entirely the 
compiler won’t gain the benefit of the information available from 
an assert.

There is of course the difficulty that the non-static assert can 
not (necessarily) be evaluated at compile-time. But of course the 
_bool value_ of the assert text-expression is always known.

Is there a way of testing whether or not something can be 
evaluated at compile-time or really requires run-time evaluation? 
If so, is it something we could use routinely? I could really use 
this in certain templates, for the case where there are several 
specialisations that use parameters with special constant values 
and then there is the ‘otherwise’ default expansion of the 
template, which has an argument that is not a known compile-time 
constant.

So could non-static asserts that do not in fact require run-time 
evaluation be convertible to an effective status assert, with all 
the benefits possible in code generation?