union

Union pragma

The union pragma can be applied to any object type. It means all of the object\'s fields are overlaid in memory. This produces a union{.interpreted-text role="c"} instead of a struct{.interpreted-text role="c"} in the generated C/C++ code. The object declaration then must not use inheritance or any GC\'ed memory but this is currently not checked.

Future directions: GC\'ed memory should be allowed in unions and the GC should scan unions conservatively.