How to insert code in place with templates/mixins?

[bachmeier]

On Monday, 20 December 2021 at 18:23:44 UTC, rempas wrote:
> On Monday, 20 December 2021 at 18:12:35 UTC, Stanislav Blinov 
> wrote:
>>
>> https://dlang.org/spec/traits.html#identifier
>
> Thanks!!! Finally I was able to do it! The code is the 
> following (well not in my final project but it's a 
> demonstration):
>
> ```
> enum add_char(string c) =
>   `if (stdout_index < STDOUT_BUF_LEN) {
>     stdout_buffer[stdout_index++] =` ~ c ~ `;
>     continue;
>   } else {
>     sys_write(1, stdout_buffer.ptr, cast(i32)stdout_index);
>     stdout_index = 0;
>     stdout_buffer[stdout_index++] =` ~ c ~ `;
>     continue;
>   }`;
>
> void main() {
>   mixin(add_char!(__traits(identifier, c)));
> }
> ```
>
> I don't know if there is another way to do it but this works 
> for me. Also another thing that I want to ask is if the "mixin" 
> is generated every time inside a loop and if there is a better 
> way to do that?

You can see the ["String mixins" section 
here](http://ddili.org/ders/d.en/mixin.html) for more details. 
Mixins are generated at compile time, so if you're referring to a 
string mixin inside a runtime loop, the code will not be 
generated every time the loop runs.