Can't Compile Global Semaphores?

[Steven Schveighoffer via Digitalmars-d-learn]

On 7/27/15 3:10 PM, Jack Stouffer wrote:
> Hi,
>
> I am currently working through a book on the fundamentals of computer
> concurrency and I wanted to do all of the exercises in D. But I ran into
> a problem when I tried to have a global semaphore:
>
> /usr/local/Cellar/dmd/2.067.1/include/d2/core/sync/semaphore.di(35):
> Error: constructor core.sync.semaphore.Semaphore.this
> core.sync.semaphore.Semaphore cannot be constructed at compile time,
> because the constructor has no available source code
>
> Here is my code:
>
> import core.sync.semaphore;
> import core.thread;
> import std.string;
> import std.stdio;
>
> shared string data;
> shared Semaphore sem = new Semaphore();

This tries to create a new Semaphore class instance at compile time.

Instead, do this:

shared Semaphore sem;
shared static this() {
    sem = new Semaphore();
}

Which will run during runtime startup.

Or, you can initialize in main().

-Steve