fn addExtra(astgen: *AstGen, extra: anytype) Allocator.Error!u32
fn addExtra(astgen: *AstGen, extra: anytype) Allocator.Error!u32 { const field_count = std.meta.fieldNames(@TypeOf(extra)).len; try astgen.extra.ensureUnusedCapacity(astgen.gpa, field_count); return addExtraAssumeCapacity(astgen, extra); }