On Thursday, 12 January 2023 at 08:03:34 UTC, John Chapman wrote:
I'm obviously doing something wrong, but don't quite understand.
```d
mixin template helper() {
mixin("writeln(12);");
}
struct Foo {
void opDispatch(string name)() {
import std.stdio;
mixin helper!();
//mixin("writeln(12);");
}
}
void main() {
Foo.init.opDispatch!"bar"();
}
```
The compiler emits these errors about the mixin
("writeln(12);"):
unexpected `(` in declarator
basic type expected, not `12`
found `12` when expecting `)`
no identifier for declarator `writeln(_error_)`
semicolon expected following function declaration
declaration expected, not `)`
Why does the commented code work but the mixin not? Thanks for
any pointers.
`mixin template` cannot be used like that. The only statement it
accepts are declaration statements: Look at
https://dlang.org/spec/module.html#MixinDeclaration
It says it must compile to a valid DeclDef, which means you can't
put code like that.
Mixin templates are used only for declaring new variables, types
and functions, it can't simply put call statements like that. You
could do this by simply calling a function such as:
```d
void helper()
{
writeln(12);
}
```
I think you'll need to comment more on your problem if you wish
specialized help
