Get and add to function body

[Jonathan M Davis]

On Thursday, October 12, 2017 23:33:39 Psychological Cleanup via 
Digitalmars-d-learn wrote:
> Is there any way to get the function body of a function,
> delegate, and lambda? I'd also like to extend functions by
> "wrapping" them at compile time generically. For example, I'd
> like to get all the properties of a class and add some code to
> them(sort of like adding a scope, prolog, and/or epilog).
>
> Is any of this possible in D?

You can introspect on symbols in D using __traits, std.traits, and is
expressions, and that will allow you to get a function's signature, but it
is not possible to get at the function's body. If you want to extend a
function by wrapping it, you can certainly generate a wrapper, but that will
mean generating a new function that calls the original and not doing
anything with the code inside of the original function. You cannot alter
existing code when generating code at compile time. You can just examine
existing code and generate new code.

- Jonathan M Davis