I need my struct defined as isZeroInit, so can I can import them as di file. (this also reduce build size)

But I find this problem with float inside union:

struct test_t {
    union {
        int i32;
        float f32;
    }
}

static assert(__traits(isZeroInit, test_t) );

Error: static assert:  `__traits(isZeroInit, test_t)` is false

I consider this is compiler bug (it may take years to get fixed), so I am here to ask any way to workaround this problem?

On Friday, 20 September 2024 at 09:38:54 UTC, Dakota wrote:

I've sent issues for compiler bugs and had them fixed within the next release—about month, not years.

Also yes, this seems to be a compiler bug; unless there's some special case missing from the spec.

On Friday, 20 September 2024 at 09:38:54 UTC, Dakota wrote:

struct test_t {
    union {
        int i32;
        float f32;
    }
}

static assert(__traits(isZeroInit, test_t) );

Error: static assert:  `__traits(isZeroInit, test_t)` is false

union somevalue{
    int i32;
    float f32;
}

struct test_t{
    somevalue a=void;
}

static assert(__traits(isZeroInit, test_t));
unittest{
  test_t foo;
  assert(foo.a.i32==0);
}

this version compiles, but you probably need to provide more details

On Friday, 20 September 2024 at 09:38:54 UTC, Dakota wrote:

struct test_t {
    union {
        int i32;
        float f32;
    }
}

static assert(__traits(isZeroInit, test_t) );

Error: static assert:  `__traits(isZeroInit, test_t)` is false

Fix: https://github.com/dlang/dmd/pull/16858

Write = void for each field with non-zero init:

    union {
        int i32;
        float f32 = void;
    }

Thanks to Dennis for the workaround.

On Friday, 20 September 2024 at 16:21:10 UTC, Nick Treleaven wrote:

Thanks your all for the tips, void solution fix me problem.