Hi, I'm attempting to use my 3D-API wrapper sokol_gfx.h from zig, I got pretty far (importing the C header works, linking with the C implementation source also works), but now I'm hitting a snag when trying to setup 'option-bag structs' that are handed to the sokol_gfx API.

It looks like zig requires that all struct members must be initialized when the struct is 'instantiated', sokol_gfx uses an 'option bag philosophy': non-initialized struct members are assumed to be zero-initialized, which for sokol-gfx indicates that default-values are to be used for such fields. This works nicely with C99-style designated initialization, which sets missing fields to zero.

For instance there are structs like sg_pipeline_desc, which all in all have dozens of members (in embedded structs): https://github.com/floooh/sokol/blob/a3057b13ba38d2d554a7f04e063f6550b2cc8bcb/sokol_gfx.h#L1422

Usually, only a small number of sg_pipeline_desc members are initialized, for instance:

    sg_pipeline pip = {
        .layout = {
            .buffers[0].stride = 28,
            .attrs = {
                [0] = { .name="position", .format=SG_VERTEXFORMAT_FLOAT3 },
                [1] = { .name="color0", .format=SG_VERTEXFORMAT_FLOAT4 }
            }
        },
        .shader = shd,
        .index_type = SG_INDEXTYPE_UINT16,
        .depth_stencil = {
            .depth_compare_func = SG_COMPAREFUNC_LESS_EQUAL,
            .depth_write_enabled = true,
        },
        .rasterizer.cull_mode = SG_CULLMODE_BACK,
    });

Currently zig complains about all missing struct members in the imported C structs, and in my case, providing an initialization for all struct members manually to 0 wouldn't make sense, the sokol_gfx API would be unusable.

Is there a simple solution to this problem which I missed? Maybe an option for the "@Cinclude()" process?

Also, what's zig's 'best practice' for such 'option-bag' APIs when written in pure zig? As far as I have seen, struct members cannot be assigned a default value, and all members must be initialized, but this gets a bit ugly if there are more than a handful members.