Unions are rejected by the compiler, and yet structs are not. --- union a_union { int iv; float fv; };
@ibuclaw created dlang/dmd pull request #12575 "fix Issue 21963 - importC: Support declaring union types" fixing this issue: - fix Issue 21963 - importC: Support declaring union types https://github.com/dlang/dmd/pull/12575
Committed as https://github.com/dlang/dmd/commit/2453350ae801d689d25f2b89d3a63897091fdfbb