Implicit type conversion depending on assignment

[Ali Çehreli]

On 3/23/23 07:36, Alexander Zhirov wrote:

 >      @property auto toString(T)()

The name is misleading because you want types other than string as well.

 >      alias toString this;

That should have been a compilation error because 'toString' does not 
have a known type (because it depends on a template parameter). How can 
the compiler accept that 'alias this'?

 > int myInt       = a;
 > float myFloat   = b;

Since you need to spell out 'int' and 'float' in some form anyway, the 
following would be my choice, which I did use in my code before:

struct MyVal
{
     private string value;

     auto to(T)()
     {
         import std.conv : to;
         return value.to!T;
     }
}

void main() {
     auto a = MyVal("100");
     auto b = MyVal("11.2");

     auto myInt = a.to!int;
     auto myFloat = b.to!float;
}

Should it be an error to convert 'a' to float? If so, the following 
modules may be helpful:

   https://dlang.org/phobos/std_sumtype.html

   https://dlang.org/phobos/std_variant.html

Ali