• Anton Pastukhov (20/20) Dec 23 2024 I'm stuck on a simple problem.
• bauss (9/29) Dec 23 2024 Simply cast el to a string instead of using std.conv.to, that way
• Anton Pastukhov (3/4) Dec 23 2024 Thanks much, it worked! Though I'm confused why. Could you please
• Jim Balter (17/21) Dec 23 2024 I had the exact same issue yesterday. Allow me to quote ChatGPT:
• Anton Pastukhov (5/6) Dec 24 2024 Thanks. That sounds plausible but I got burned by ChatGPT more
• monkyyy (6/14) Dec 24 2024 Id argue that the problem is that d's type system keeps track of
• IchorDev (7/11) Dec 28 2024 Well, `to!string` gets a *string representation* of a value. For
• Ogion (7/14) Dec 27 2024 Or use `std.conv.asOriginalType` to avoid implicit cast:

Anton Pastukhov <mail anton9.com> writes:

I'm stuck on a simple problem.
There is this string enum of MIME types:

```d
enum BodyType: string {
     PlainText = "text/plain",
     JSON = "apllication/json",
     FormUrlencoded = "application/x-www-form-urlencoded",
     Multipart = "multipart/form-data",
     Other = "Other",
     None = "None"
}
```

Q: how can I iterate its values? With keys it's relatively easy:

```d
auto keys = [EnumMembers!BodyType]
     .map!(el => to!string(el))
     .array;

```
With values, though, I'm kinda stuck. Reading Ali's book and 
https://dlang.org/spec/enum.html did not bring enlightening

bauss <jacobbauss gmail.com> writes:

On Monday, 23 December 2024 at 20:20:02 UTC, Anton Pastukhov 
wrote:
 I'm stuck on a simple problem.
 There is this string enum of MIME types:

 ```d
 enum BodyType: string {
     PlainText = "text/plain",
     JSON = "apllication/json",
     FormUrlencoded = "application/x-www-form-urlencoded",
     Multipart = "multipart/form-data",
     Other = "Other",
     None = "None"
 }
 ```

 Q: how can I iterate its values? With keys it's relatively easy:

 ```d
 auto keys = [EnumMembers!BodyType]
     .map!(el => to!string(el))
     .array;

 ```
 With values, though, I'm kinda stuck. Reading Ali's book and 
 https://dlang.org/spec/enum.html did not bring enlightening

Simply cast el to a string instead of using std.conv.to, that way 
you retrieve the values.

```
auto values = [EnumMembers!BodyType]
     .map!(el => cast(string)el)
     .array;
```

Anton Pastukhov <mail anton9.com> writes:

On Monday, 23 December 2024 at 20:26:47 UTC, bauss wrote:

 Simply cast el to a string instead of using std.conv.to

Thanks much, it worked! Though I'm confused why. Could you please 
elaborate?

Jim Balter <jqbalter gmail.com> writes:

On Monday, 23 December 2024 at 20:32:58 UTC, Anton Pastukhov 
wrote:
 On Monday, 23 December 2024 at 20:26:47 UTC, bauss wrote:

 Simply cast el to a string instead of using std.conv.to

 Thanks much, it worked! Though I'm confused why. Could you 
 please elaborate?

I had the exact same issue yesterday. Allow me to quote ChatGPT:


You're correct that .to!string also produces the member name 
rather than the value of the enum, which can be confusing. This 
behavior occurs because .to!string calls the toString function 
defined for the enum type, which defaults to returning the name 
of the enum member rather than its associated value.

Why .to!string behaves this way:
Enums in D are designed to emphasize their symbolic names over 
their values. The toString implementation for enums is tailored 
to reflect this by default, focusing on member names instead of 
their underlying values. The std.conv.to function, when applied 
to an enum, invokes this toString behavior.

Correct way to get the value:
If you want to convert the underlying value of the enum member to 
a string, you must explicitly cast the enum to its base type.

Anton Pastukhov <mail anton9.com> writes:

On Monday, 23 December 2024 at 23:46:33 UTC, Jim Balter wrote:
 I had the exact same issue yesterday. Allow me to quote ChatGPT:

Thanks. That sounds plausible but I got burned by ChatGPT more 
than once, so I still would like to hear from a human being. 
Generally GhatGPT is not very good with D and hallucinates pretty 
often

monkyyy <crazymonkyyy gmail.com> writes:

On Tuesday, 24 December 2024 at 12:07:56 UTC, Anton Pastukhov 
wrote:
 On Monday, 23 December 2024 at 23:46:33 UTC, Jim Balter wrote:
 I had the exact same issue yesterday. Allow me to quote 
 ChatGPT:

 Thanks. That sounds plausible but I got burned by ChatGPT more 
 than once, so I still would like to hear from a human being. 
 Generally GhatGPT is not very good with D and hallucinates 
 pretty often

Id argue that the problem is that d's type system keeps track of 
enum-ness in a strange way

https://github.com/crazymonkyyy/debuglibprototype/blob/master/old/humanname.d

 if(!is(T == enum))

rapidly becomes nessery to spam everywhere

IchorDev <zxinsworld gmail.com> writes:

On Monday, 23 December 2024 at 20:32:58 UTC, Anton Pastukhov 
wrote:
 On Monday, 23 December 2024 at 20:26:47 UTC, bauss wrote:

 Simply cast el to a string instead of using std.conv.to

 Thanks much, it worked! Though I'm confused why. Could you 
 please elaborate?

Well, `to!string` gets a *string representation* of a value. For 
an enum, that's its member name. `cast(string)` just converts the 
enum value to its base type. Practically speaking, you can 
probably just use `[EnumMembers!BodyType]`, since `BodyType` will 
implicitly convert to its base-type of `string` anyway.

Ogion <ogion.art gmail.com> writes:

On Monday, 23 December 2024 at 20:26:47 UTC, bauss wrote:
 Simply cast el to a string instead of using std.conv.to, that 
 way you retrieve the values.

 ```
 auto values = [EnumMembers!BodyType]
     .map!(el => cast(string)el)
     .array;
 ```

Or use `std.conv.asOriginalType` to avoid implicit cast:

```D
auto values = [EnumMembers!BodyType]
      .map!asOriginalType
      .array;
  ```