Holes in structs and opEquals

[Walter Bright]

yigal chripun wrote:
> The compiler knows at compile-time what variables are initialized with "=void". The compiler than can add a compilation error when such a struct variable is used in an equals expression. 
> this doesn't cover use of malloc() which must be the user's responsebility. 
> 
> e.g.
>  S s1=void,s2=void;
>  s1.s=0; s1.d=0;
>  s2.s=0; s2.d=0;
>  assert(s1 == s2); // <- this line should not compile
> 

It can, but I don't agree that it should. For an =void initialization, 
it's the user's responsibility to initialize it properly. The use of 
=void implies the user knows what he's doing with it, and will take care 
to initialize the 'holes' as necessary.

Trying to disable == for such structs is a losing battle, anyway, as the 
compiler could only detect the most obvious cases. Pass a reference to 
it to a function, store it in a data structure, etc., and all that goes 
away.