On Tue, 24 Aug 2010 18:19:25 -0400, Andrej Mitrovic
<[email protected]> wrote:
What I don't understand is how the constructor can be called like that.
In my example the mixin would convert the code to:
return CheckedInt(10);
But if I ever tried a call like "CheckedInt(10)" in a unittest block, it
wouldn't work. So how does this magic work?
BTW, a unit test model I use in dcollections quite a bit is putting unit
tests inside the template itself. Then the unit test enjoys the same
benefits. e.g.:
struct CheckedInt(N) if(isIntegral!N)
{
void foo(N n)
{
...
}
unittest
{
CheckedInt ci;
ci.foo(1);
}
}
The only caveat is you have to instantiate the template to get the unit
test to run :) So on the bottom of your module you have to do this:
unittest
{
CheckedInt!int ci1;
CheckedInt!uint ci2;
...
}
The great benefit however is if you write your unit tests in a generic
way, you can rigorously test your struct with all possible template
instantiations without writing any extra code. I've found the only limit
here is generating data -- the literals have to match the N type.
CheckedInt only instantiates if N is integral, but if that constraint
wasn't there, then CheckedInt!string wouldn't compile because the unit
test can't convert the literal 1 to a string.
-Steve
