Old code no longer working on any DMD compilers

[Mike Parker]

On Friday, 6 September 2019 at 05:59:30 UTC, Jamie wrote:

> time and fmod is called so it breaks. In case 3, with default 
> struct arguments, I thought that the constructor I have defined 
> was being called, however the default constructor was being 
> called (this()) so fmod wasn't being called.
>
> The reason why my old code worked was because it used the 
> default arguments and I wasn't actually calling the constructor 
> I defined. When I removed the default arguments in the 
> constructor and tried case 2 it obviously didn't work.
>
> Am I understanding correctly? Thanks

You're right about case 1 and case 2, and partially correct about 
case 3. Structs don't actually have default constructors. They 
have default *initializers*. In other words, s = S() is the same 
as s = S.init. See item #4 in the documentation for struct 
destructors [1]:

"If the ParameterList is empty, the struct instance is default 
initialized."

So yes, your constructor is not being called.

1. https://dlang.org/spec/struct.html#struct-constructor