• tastyminerals (17/17) Oct 14 2021 The new `DMD v2.097.2` deprecated implicit null conversions
• jfondren (14/24) Oct 14 2021 Do you have a complete example? Because this runs without error:
• tastyminerals (3/31) Oct 15 2021 Steven Schveighoffer was correct, the error was caused by non
• Steven Schveighoffer (9/14) Oct 15 2021 As a note for future reference, as jfondren says it's always good to
• Steven Schveighoffer (16/37) Oct 14 2021 I think your expression is something more like:

tastyminerals <tastyminerals gmail.com> writes:

The new `DMD v2.097.2` deprecated implicit null conversions 
`std.typecons.Nullable!double.Nullable.get_`.

The deprecation warning tell you to `Please use .get explicitly.`.

Here is an example code that doesn't work with the new compiler 
anymore:

```
if (someValue.isNull)
```

Attempting to run the above throws:
```
Error: incompatible types for `(0) : (someValue)`: `int` and 
`Nullable!int`
```

I am not sure I understand what kind of `.get` overload are we 
supposed to use here. I tried to read the documentation but looks 
like it is yet to be updated.

Can somebody please help me out?

jfondren <julian.fondren gmail.com> writes:

On Thursday, 14 October 2021 at 11:58:29 UTC, tastyminerals wrote:
 Here is an example code that doesn't work with the new compiler 
 anymore:

 ```
 if (someValue.isNull)
 ```

 Attempting to run the above throws:
 ```
 Error: incompatible types for `(0) : (someValue)`: `int` and 
 `Nullable!int`
 ```

Do you have a complete example? Because this runs without error:

```d
import std.typecons : nullable, Nullable;
import std.stdio : writeln;

void main() {
     auto a = nullable(1);
     auto b = Nullable!int.init;
     if (!a.isNull)
         writeln(a.get);
     if (b.isNull)
         writeln("b is null");
}
```

tastyminerals <tastyminerals gmail.com> writes:

On Thursday, 14 October 2021 at 12:43:36 UTC, jfondren wrote:
 On Thursday, 14 October 2021 at 11:58:29 UTC, tastyminerals 
 wrote:
 Here is an example code that doesn't work with the new 
 compiler anymore:

 ```
 if (someValue.isNull)
 ```

 Attempting to run the above throws:
 ```
 Error: incompatible types for `(0) : (someValue)`: `int` and 
 `Nullable!int`
 ```

 Do you have a complete example? Because this runs without error:

 ```d
 import std.typecons : nullable, Nullable;
 import std.stdio : writeln;

 void main() {
     auto a = nullable(1);
     auto b = Nullable!int.init;
     if (!a.isNull)
         writeln(a.get);
     if (b.isNull)
         writeln("b is null");
 }
 ```

Steven Schveighoffer was correct, the error was caused by non 
explicit `someVar;` which had to be changed to `someVar.get;`.

Steven Schveighoffer <schveiguy gmail.com> writes:

On 10/15/21 6:39 AM, tastyminerals wrote:
 On Thursday, 14 October 2021 at 12:43:36 UTC, jfondren wrote:

 Do you have a complete example? Because this runs without error:



 
 Steven Schveighoffer was correct, the error was caused by non explicit 
 `someVar;` which had to be changed to `someVar.get;`.

As a note for future reference, as jfondren says it's always good to 
post the exact code that is failing, better yet a complete example we 
can run. Often times people (including myself and many long-time users) 
come here puzzled about some message, but we have focused our brain on 
something that we think is causing the problem, but it isn't. Just 
posting that small piece brings us into your focused confusion instead 
of really looking at the big picture ;)

-Steve

Steven Schveighoffer <schveiguy gmail.com> writes:

On 10/14/21 7:58 AM, tastyminerals wrote:
 The new `DMD v2.097.2` deprecated implicit null conversions 
 `std.typecons.Nullable!double.Nullable.get_`.
 
 The deprecation warning tell you to `Please use .get explicitly.`.
 
 Here is an example code that doesn't work with the new compiler anymore:
 
 ```
 if (someValue.isNull)
 ```
 
 Attempting to run the above throws:
 ```
 Error: incompatible types for `(0) : (someValue)`: `int` and `Nullable!int`
 ```
 
 I am not sure I understand what kind of `.get` overload are we supposed 
 to use here. I tried to read the documentation but looks like it is yet 
 to be updated.
 
 Can somebody please help me out?

I think your expression is something more like:

```d
someValue.isNull ? 0 : someValue;
```

Due to the error message format. You need to call `get` explicitly to 
unwrap a Nullable now. So change it to:

```d
someValue.isNull ? 0 : someValue.get;
```

or even better:

```d
someValue.get(0);
```

which uses the default value of 0 if it's null.

-Steve