Movement against float.init being nan

[Paul Backus]

On Tuesday, 23 August 2022 at 21:53:35 UTC, Ali Çehreli wrote:
> On 8/23/22 14:40, Dave P. wrote:
>
> >> And yes, 0 happens to be a valid garbage value.
> >
> > The default value for a struct imported via importC is all
> bits 0.
>
> Steve said the same thing but I don't see it on the ImportC 
> page (yet?):
>
>   https://dlang.org/spec/importc.html
>
> I wonder why D would do that.

Global and static variables in C are initialized to all-zero 
bits, regardless of type. Here's the relevant paragraph from the 
C11 standard:

> If an object that has automatic storage duration is not 
> initialized explicitly, its value is indeterminate. If an 
> object that has static or thread storage duration is not 
> initialized explicitly, then:
> 
>     if it has pointer type, it is initialized to a null pointer;
>     if it has arithmetic type, it is initialized to (positive 
> or unsigned) zero;
>     if it is an aggregate, every member is initialized 
> (recursively) according to these rules, and any padding is 
> initialized to zero bits;
>     if it is a union, the first named member is initialized 
> (recursively) according to these rules, and any padding is 
> initialized to zero bits;

Source: http://port70.net/~nsz/c/c11/n1570.html#6.7.9p10

Presumably this behavior was implemented in an attempt to conform 
to this part of the C standard.