Movement against float.init being nan

[jmh530]

On Tuesday, 23 August 2022 at 11:08:36 UTC, Zoadian wrote:
> On Tuesday, 23 August 2022 at 00:50:21 UTC, Walter Bright wrote:
>> C and C++ initialize them to garbage unless it is a 
>> global/static variable. That's probably the worst option, as 
>> it results in Heisenbugs that are very hard to track down.
>
> I agree that NaN for uninitialized floats is the best option.
> However, can we get a switch to force initialization of floats? 
> it would be of great help to quickly find the place where one 
> forgot to initialize a variable.

Walter makes good points in favor of NaN as a default, but I 
agree this would be useful for identifying the source of the 
problem, so long as it is primarily used for debugging purposes. 
For instance, if we could do something like 
`debug(force-float-initialization, VALUE)` where VALUE defaults 
to zero but represents the value that uninitialized floats would 
get initialized to, then that would be helpful (a pragma might be 
an alternative to a debug statement). After all, if you are 
writing a function that unexpectedly returns a NaN, then you can 
put that up top and see if it returns something else. Being able 
to modify the VALUE would help identify the issue in more 
complicated functions.