On Wed, 23 Jun 2010 16:06:48 -0400, Tomek Sowiński <j...@ask.me> wrote:
Dnia 22-06-2010 o 23:55:29 Michal Minich <michal.min...@gmail.com>
napisał(a):
On Tue, 22 Jun 2010 17:30:23 -0400, Steven Schveighoffer wrote:
On Tue, 22 Jun 2010 17:07:02 -0400, Tomek Sowiński <j...@ask.me> wrote:
Yes, why? It could be implemented in object.d in a similar fashion as
std.contracts.enforce. Does it do anything special that a library
function couldn't?
all calls to assert are removed by the compiler in release mode. I
don't think there's a way to implement that via a library (it would be
nice though!)
-Steve
modifying 'debug' attribute which decorate a function, which new meaning
that all calls to it are removed in release mode, might do the trick :)
it also could be useful for logging.
That means you have to compile with -debug switch. Assert is enabled
without any switches.
AFAIK, now the attribute means that the function does not exists in
debug
mode, but that also means that you must mark all calls to it with
'debug'
which I don't find so much useful...
There's a better way:
void assert_(string file = __FILE__, uint line = __LINE__)(bool pred,
lazy string msg = null) {
version(unittest)
if (!pred)
throw new AssertError(msg, file, line);
}
If unittesting is off, it is inlined and all calls vanish.
Only if you specify -inline on the command line... Not a good option.
Someone mentioned the assert(0) special case. That could be implemented
like:
void fail() {
asm {
// HLT instruction...
}
}
Following benefits spring to mind:
- It's clear that fail is something different than assert. Unlike
assert vs. assert(0).
- The compiler can be made aware of fail() to recognize and refuse to
compile dead code.
- Documentation can be added with no additional effort; newbies can
read it straight from a tooltip provided by the IDE.
- Curious users are free to introspect the implementation.
So I ask again -- what benefits on top of that list can having assert in
the language give?
Well, first, you can't implement it in the library as currently designed
without requiring special switches for normal compilation.
No need to have any more reasons.
What are the drawbacks? "keyword bloat" is an academic measure, and
doesn't count ;)
-Steve
