-
Notifications
You must be signed in to change notification settings - Fork 73
Expand file tree
/
Copy pathoptional_type.cc
More file actions
68 lines (54 loc) · 2.07 KB
/
Copy pathoptional_type.cc
File metadata and controls
68 lines (54 loc) · 2.07 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <cstddef>
#include "absl/base/attributes.h"
#include "absl/strings/string_view.h"
#include "common/type.h"
namespace cel {
namespace common_internal {
namespace {
struct OptionalTypeData final {
const absl::string_view name;
const size_t parameters_size;
const Type parameter;
};
// Here by dragons. In order to make `OptionalType` default constructible
// without some sort of dynamic static initializer, we perform some
// type-punning. `OptionalTypeData` and `OpaqueTypeData` must have the same
// layout, with the only exception being that `OptionalTypeData` as a single
// `Type` where `OpaqueTypeData` as a flexible array.
union DynOptionalTypeData final {
OptionalTypeData optional;
OpaqueTypeData opaque;
};
static_assert(offsetof(OptionalTypeData, name) ==
offsetof(OpaqueTypeData, name));
static_assert(offsetof(OptionalTypeData, parameters_size) ==
offsetof(OpaqueTypeData, parameters_size));
static_assert(offsetof(OptionalTypeData, parameter) ==
offsetof(OpaqueTypeData, parameters));
ABSL_CONST_INIT const DynOptionalTypeData kDynOptionalTypeData = {
.optional =
{
.name = OptionalType::kName,
.parameters_size = 1,
.parameter = DynType(),
},
};
} // namespace
} // namespace common_internal
OptionalType::OptionalType()
: opaque_(&common_internal::kDynOptionalTypeData.opaque) {}
Type OptionalType::GetParameter() const { return GetParameters().front(); }
} // namespace cel