07.07.2013 17:12, Tommi пишет:
On Sunday, 7 July 2013 at 12:30:28 UTC, Andrej Mitrovic wrote:
On 7/7/13, Tommi <tommitiss...@hotmail.com> wrote:
Sometimes you need to have some extra data to check against in
the assert expression. That data isn't needed in release mode
when assertions are ignored. Therefore, you put that extra data
inside a version(assert). But then those assertions fail to
compile in release mode because the symbol lookup for that extra
data fails. For this reason, assert statements should live inside
version(assert) blocks by default.
I've ran into an issue when implementing this feature back in February
(see the pull request):
http://d.puremagic.com/issues/show_bug.cgi?id=9450
https://github.com/D-Programming-Language/dmd/pull/1614
Oh, should have searched bugzilla before posting this.
But would it be possible to implement it something like:
During a release build, even though version(assert) blocks are compiled
out of existence, the compiler would keep a separate list of symbols
(and other info) of the things declared inside those version(assert)
blocks. Then, when parsing assert expressions, if an undefined symbol is
found, the compiler would check that separate list of symbols that it
has been keeping, and if the symbol is found there and use of the symbol
is syntactically correct, the compiler would just keep on going instead
of spewing an "unidentified identifier" error.
That way we'd make sure that things like:
assert(this_identifier_doesnt_exist < 12);
...wouldn't compile.
It's always a bad idea to add special cases like this one for
`version(assert)`. Anyway one will get into huge troubles trying to
implement such stuff as I even can't imagine how it can be implemented
consistently.
--
Денис В. Шеломовский
Denis V. Shelomovskij
