First Impressions!

[A Guy With an Opinion]

On Tuesday, 28 November 2017 at 04:17:18 UTC, A Guy With an 
Opinion wrote:
> On Tuesday, 28 November 2017 at 04:12:14 UTC, ketmar wrote:
>> A Guy With an Opinion wrote:
>>
>>> That is true, but I'm still unconvinced that making the 
>>> person's program likely to error is better than initializing 
>>> a number to 0. Zero is such a fundamental default for so many 
>>> things. And it would be consistent with the other number 
>>> types.
>> basically, default initializers aren't meant to give a "usable 
>> value", they meant to give a *defined* value, so we don't have 
>> UB. that is, just initialize your variables explicitly, don't 
>> rely on defaults. writing:
>>
>> 	int a;
>> 	a += 42;
>>
>> is still bad code, even if you're know that `a` is guaranteed 
>> to be zero.
>>
>> 	int a = 0;
>> 	a += 42;
>>
>> is the "right" way to write it.
>>
>> if you'll look at default values from this PoV, you'll see 
>> that NaN has more sense that zero. if there was a NaN for 
>> ints, ints would be inited with it too. ;-)
>
> Eh...I still don't agree. I think C and C++ just gave that 
> style of coding a bad rap due to the undefined behavior. But 
> the issue is it was undefined behavior. A lot of language 
> features aim to make things well defined and have less verbose 
> representations. Once a language matures that's what a big 
> portion of their newer features become. Less verbose shortcuts 
> of commonly done things. I agree it's important that it's well 
> defined, I'm just thinking it should be a value that someone 
> actually wants some notable fraction of the time. Not something 
> no one wants ever.
>
> I could be persuaded, but so far I'm not drinking the koolaid 
> on that. It's not the end of the world, I was just confused 
> when my float was NaN.

Also, C and C++ didn't just have undefined behavior, sometimes it 
has inconsistent behavior. Sometimes int a; is actually set to 0.