How to pass variables to string mixins?

[Benjamin Schaaf]

On Tuesday, 26 February 2019 at 00:07:54 UTC, Victor Porton wrote:
> I want to create a string mixin based on a supplementary 
> variable (name2 below):
>
> Let we have something like:
>
> mixin template X(string name) {
>   immutable string name2 = '_' ~ name;
>   mixin("struct " ~ name2 ~ "{ int i; }");
> }
>
> But it would create variable name2 inside X, which should not 
> be created. How to solve this problem?

Your best bet is to just not declare anything in a mixin template 
that you don't want included:

mixin template X(string name) {
   mixin("struct _" ~ name ~ "{ int i; }");
}

Or don't use mixin templates:

template X(string name) {
   immutable string name2 = '_' ~ name;
   enum X = "struct " ~ name2 ~ "{ int i; }";
}
mixin(X!("foo"));