February 24, 2020
https://issues.dlang.org/show_bug.cgi?id=20605

          Issue ID: 20605
           Summary: static constructor in template run after usage
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Keywords: spec, wrong-code
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: schveiguy@yahoo.com

In the spec, under static constructors (https://dlang.org/spec/class.html#static-constructor), it states:

Static constructors within a module are executed in the lexical order in which they appear. All the static constructors for modules that are directly or indirectly imported are executed before the static constructors for the importer.

However, this is not the case if the static constructor is inside a template. Instead, the first instantiation of the template counts as the order it is executed:

template T() {
   int* T;
   static this() {
     T = new int;
   }
}

int x;
static this() { // executed first
   x = *T!(); // instantiated static ctor executed second.
}

This will segfault, even though the lexical order should make it work properly.

The compiler should order the static constructor pieces in lexical order of the file. This should be enough to be able to properly initialize items.

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