Re: Metaprogramming, generate argument list.

[Jack Applegame via Digitalmars-d-learn]

On Monday, 22 August 2016 at 22:01:51 UTC, ciechowoj wrote:
Is it possible to generate an argument list that contains 
pointers to local variables at compile time?

For example, consider following code:

template Repeat(alias int N, alias variable)
{
    // Magic

    alias Repeat = /* Even more magic */;
}

void foo(int* x, int* y, int* z)
{
    // [...]
}

void fun()
{
    int bar = 42;

    foo(Repeat!(3, bar)); // want to replace it with &bar, 
&bar, &bar
}
This is impossible since pointers to local variables are unknown 
at compile time. But you can generate arguments list that 
contains functions that return pointers at run-time:

template Repeat(int N, alias variable) {
        auto ptr() @property { return &variable; }
        import std.meta : AliasSeq;
        static if(N == 1) alias Repeat = ptr;
        else alias Repeat = AliasSeq!(ptr, Repeat!(N-1, variable));
}

void foo(int* x, int* y, int* z) {
}

void main() {
    int bar = 42;
    foo(Repeat!(3, bar));
}