xref: /aosp_15_r20/external/stg/hex.h (revision 9e3b08ae94a55201065475453d799e8b1378bea6)
1 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
2 // -*- mode: C++ -*-
3 //
4 // Copyright 2023-2024 Google LLC
5 //
6 // Licensed under the Apache License v2.0 with LLVM Exceptions (the
7 // "License"); you may not use this file except in compliance with the
8 // License.  You may obtain a copy of the License at
9 //
10 //     https://llvm.org/LICENSE.txt
11 //
12 // Unless required by applicable law or agreed to in writing, software
13 // distributed under the License is distributed on an "AS IS" BASIS,
14 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 // See the License for the specific language governing permissions and
16 // limitations under the License.
17 //
18 // Author: Giuliano Procida
19 
20 #ifndef STG_HEX_H_
21 #define STG_HEX_H_
22 
23 #include <cstddef>  // for std::size_t
24 #include <functional>  // for std::hash
25 #include <ios>
26 #include <ostream>
27 
28 namespace stg {
29 
30 template <typename T>
31 struct Hex {
HexHex32   explicit Hex(const T& value) : value(value) {}
33   auto operator<=>(const Hex<T>& other) const = default;
34   T value;
35 };
36 
37 template <typename T> Hex(const T&) -> Hex<T>;
38 
39 template <typename T>
40 std::ostream& operator<<(std::ostream& os, const Hex<T>& hex_value) {
41   // not quite right if an exception is thrown
42   const auto flags = os.flags();
43   os << "0x" << std::hex << hex_value.value;
44   os.flags(flags);
45   return os;
46 }
47 
48 }  // namespace stg
49 
50 template <typename T>
51 struct std::hash<stg::Hex<T>> {
52   std::size_t operator()(const stg::Hex<T>& hex) const noexcept {
53     return std::hash<T>{}(hex.value);
54   }
55 };
56 
57 #endif  // STG_HEX_H_
58