On Friday, 1 August 2014 at 09:02:36 UTC, Walter Bright wrote:
On 7/31/2014 11:24 PM, "Ola Fosheim Grøstad"
<[email protected]>" wrote:
On Friday, 1 August 2014 at 02:44:51 UTC, Walter Bright wrote:
That entry makes no mention of assert being used as an
optimization hint.
Saying that a predicate is always true means it's available
to the optimizer.
An assert does not say that the predicate is always true.
Yes, it does. From Meyers' comprehensive tome on the topic
"Object-Oriented Software Construction" (1997) where he writes:
"A run-time assertion violation is the manifestation of a bug
in the software."
-- pg. 346
In fact, Meyers calls it "rule (1)" of assertions.
No, the statement in this quote does not imply that it is always
true. It says that there is a bug if it isn't, which obviously
wouldn't make any sense if the predicate were always true.
An assertion doesn't tell the compiler that a predicate is true,
it tells the compiler to _check whether_ it is true.
