On Wednesday, 6 December 2017 at 19:19:09 UTC, A Guy With a
Question wrote:
On Wednesday, 6 December 2017 at 18:09:45 UTC, Steven
Schveighoffer wrote:
On 12/6/17 12:17 PM, Steven Schveighoffer wrote:
So why wouldn't the compiler fail? Because it has no idea yet
what you mean by Nullable. It doesn't even know if Nullable
will be available or not. You could even import Nullable, but
Nullable!T may be an error.
To give an example of why the compiler waits until
instantiation:
class C(T) : T
{
void foo() { doesthisexist(); }
}
class D { void doesthisexist(); }
auto x = new C!D; // OK
auto y = new C!Object: // fail
-Steve
It also doesn't parse or do semantic checks on unit tests
unless you add the flag...apparently.
This compiles...
unittest
{
WHY DOESNT THE COMPILER FIND A PROBLEM HERE!?
}
It seems D's fast compile times are achieved by skipping
semantic checking and even parsing when it doesn't feel it's
needed. I strongly disagree with this decision. This could
leave complex dormant time bombs that break builds unexpectedly
and even accidentally.
That's why measuring the level of coverage obtained by the
unittests is important.
It's not just about the templates, standard if conditions that
are never tested can also be time bombs, standard functions that
are never tested can also be time bombs. Even more pernicious in
a way.
