On 20.11.2011 21:03, Ali Çehreli wrote:
On 11/20/2011 11:36 AM, Norbert Nemec wrote:
Collecting individual requirements as an AND expression of booleans does
not allow any helpful error message. If just one of the requirements is
not met, there is just one failure of the global assertion.
dmd 2.056 with the code that I've tried, does provide which individual
requirement is not met:
deneme.d(54697): Error: no property 'len' for type 'YourClass'
deneme.d(54709): Error: template instance
deneme.hasNonNegativeLength!(YourClass) error instantiating
deneme.d(54727): instantiated from here: matchesMyConcept!(YourClass)
True, there is some additional detail in some cases, but if you look
closely: dmd does not complain about requirements that compute as
"false", but about subexpressions that fail to compile at all.
In fact, such an error even means that the check is unusable as
constraint: A template constraint should always compile without error
and simply return true or false.
