How to use std. packages in so files written in dlang

[Mike Parker via Digitalmars-d-learn]

On Friday, 12 August 2016 at 00:57:42 UTC, grampus wrote:
> Hi,erveryone
> I am trying to use dLang to make so file for existing c/c++ 
> project.
> I followed the examples on https://dlang.org/dll-linux.html, 
> which works well.
>
> but when I replaced import core.stdc.stdio; with import 
> std.stdio；
> to use writefln() instead of printf(), then things changed.
>

To expand on ketmar's answer, support for some language features 
exists in D Runtime. If you never use those features directly or 
indirectly (which means limiting yourself to the C API, avoiding 
anything that touches the GC, no associative arrays, and so on) 
then you don't need to initialize D runtime. That's why you don't 
see the problem when calling printf, but writeln uses features 
internally that require the D Runtime and so you get the error 
when you execute the program.