convert between types

[Lars Johansson]

On Friday, 2 January 2026 at 13:09:44 UTC, Lars Johansson wrote:
>     I'm writing a simple program just to get started (se below).
>      mat[i][z] = z; this line generate following error:
>      cannot implicitly convert expression `z` of type `ulong` 
> to `char`
>
> There are a number of ways to avoid this conversion, but I'm 
> interested in best way to convert between types. How do I do 
> this conversion best D practice.
>
> Is there a cheet sheet where I can find preferably all possible 
> conversions between types?
> That sheet would save me hours and hours and lots of screaming 
> in agony.
>
>
>
>     import std.stdio;
>     void main()
>     {
>         writeln("Hello, world without explicit compilations!");
>         auto xmat = [
>             ['a','a','a','a','a','a','a','a']
>            ,['*','*','*','*','*','*','*','*']
>            ,['*','*','*','*','*','*','*','*']
>         ];
>     initmat(xmat);
>     }
>
>     void initmat (char[][] mat) {
>     import std.conv;
>         foreach (i, row; mat) {
>             foreach (z, tek; row) {
>               //  writeln(tek);
>                 mat[i][z] = z;
>             }
>         }
>     }

I found a solution wchar  cast(wchar) (z + '0');
first declare the array as wchar
then add '0' to the value
then cast(wchar) (z + '0')

I do not find this very easy to figure out. I found the 
conversion chapter in the manual from there I saw wchar is more 
likely to work. the add zero claude helped me with.
A cheet sheet would be very nice to have.

 From this I learned to hex display everything that I have 
conversion problem with.