Bug 20068 – Union initialization in constructors should be @safe

Currently, initializing a union is @safe, even if that union contains a pointer: --- union A { int i; int* p; } @safe void example(int* p) { A a = { p: p }; // compiles } --- However, if a constructor is used to initialize the union, it is considered @system: --- union B { int i; int* p; @safe this(int* p) { // Error: cannot access pointers in @safe code that overlap other fields this.p = p; } } --- Since the first example is @safe, the second example should be @safe as well.

dlang/dmd pull request #12400 "Fix 20068 - Treat initialization of unions in constructors as @safe" was merged into master: - fafefbc93f212d471b2cacf0208772e9a8d18286 by MoonlightSentinel: Fix 20068 - Treat initialization of unions in constructors as @safe Don't eagerly check the safety of a `DotVarExp` when determining whether it's modifiable and instead defer it after the `ConstructExp` lowerings. This also ensures proper error messages when initializing an immutable member twice. https://github.com/dlang/dmd/pull/12400