Dynamic code generation

[ag0aep6g via Digitalmars-d-learn]

On 07/20/2016 06:36 AM, Rufus Smith wrote:
> Does D offer any solutions to generate code dynamically?

I don't think so.

> I would like to
> order based on optimal strategies. This requires effectively hard coding
> the execution path.
>
> A simple example,
>
> if (x == true)
>     foo();
> else
>     bar();
>
> can be recoded to be foo() or bar() while x is fixed, in my case x is
> fixed for long periods and therefor the check is unnecessary. I also
> know when x changes in all cases. This is just a simple example, of
> course. I would not want to resort to assembly programming to accomplish
> this.

Just an idea:

----
void main()
{
     setX(true);
     f(); /* calls foo */
     setX(false);
     f(); /* calls bar */
}

void function() f;

void setX(bool x)
{
     if (x) f = &impl!true;
     else f = &impl!false;
}

void impl(bool x)()
{
     static if (x) foo();
     else bar();
}

void foo() { import std.stdio; writeln("foo"); }
void bar() { import std.stdio; writeln("bar"); }
----

Of course, if this is for optimization purposes, measure first if 
hard-coded is actually faster than the branch.