On 07/02/2016 02:28 PM, Uwe Stöhr wrote:
> Am 02.07.2016 um 20:15 schrieb Richard Heck:
>
>> All harmless.
>>
>> In future, you can fix these sorts of warnings easily.
>
> I understand the compiler warnings but it is not easy for me to decide
> if a truncation of values was intended or not. I mean if it is
> intended one should use int(). Since this is not done, I must assume
> that this was not intended.
This sort of thing is known as an "implicit conversion". It happens all
the time. For example, consider the following:
Type * type_ptr;
....
if (type_ptr) {
...do something...
}
This involves an implicit conversion from Type* to a bool.
You get the warning in the case of a conversion from double to int
because, as it says, there /could/ be a loss of data. But such
conversions are still quite common.
>
>> int const y_bar = deleted() ? y - fm.maxAscent() / 3
>> : y + 2 * pi.base.solidLineOffset() +
>> pi.base.solidLineThickness();
>>
>> Here, we clearly do want to do that, since the function to which
>> we're about to
>> pass y_bar wants an int, too.
>
> That is not clear to me. How can I know that we want to floor the
> result of a division. Do we really want to get 2 if fm.maxAscent() is
> either 6, 7 or 8? That is quite strange to me. Another question arises
> if we want the truncation: why do we divide by 3 not e.g. 4?
Well, there's a comment just above:
// Calculate 1/3 height of font
Granted, one might have used rounding here. But, so far as I am aware,
no bug has been reported about the drawing of change markers. And adding
int(...) does not change behavior.
> That is why I report the warnings uncommented. It might be that it is
> obvious for others but for me they are not.
As I said, you just have to read the code. If you don't understand it,
or can't figure out what's intended, then that would be the right time
to report the warning.
Richard
