John Maddock wrote:
Johan Paulsson wrote:
I wrote:
Below is the compile-time assert I use. Would it be a useful addition to Boost?
8>< snip
Frankly it's hard to choose between them on error message quality (which is to say none are all that good).
One of the requirements that came up for static asserts when BOOST_STATIC_ASSERT was talked about was a declaration like syntax, in fact both:
static_assert<condition> x;
and
typedef static_assert<condition> x;
were explicitly rejected at the time.
Thank you for looking. I prefer some kind of template, but I now realize most do not.
I also seem to remember that some compilers at the time evaluated typedefs in a lazy manner: if the typedef was unused then it was never evaluated and the static-assertion was never triggered. That's the reason for some of the convolutions inside static_assert.hpp. I suspect, however, that current compilers have moved away from such "lazyness".
That would make my implementation useless. I think it would be interesting to know that a compile-time assert should work on any standard-conforming compiler. I don't know if, for example, typedef-ining an invalid type inside a function, and then not using the type, makes the program "ill formed" and requires a "diagnostic message". Maybe the complie-time asserts in Boost should work on any standard-conforming compiler. I think that would be a good reason to use Boost and not mine. /Johan Paulsson