util/environment.h
| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // SPDX-License-Identifier: BSD-3-Clause | ||
| 2 | #pragma once | ||
| 3 | |||
| 4 | #include <iterator> | ||
| 5 | #include <optional> | ||
| 6 | #include <string> | ||
| 7 | #include <string_view> | ||
| 8 | #include <type_traits> | ||
| 9 | #include <vector> | ||
| 10 | |||
| 11 | #include "chrono_batch_render/util/text.h" | ||
| 12 | |||
| 13 | namespace chrono::batch_render { | ||
| 14 | |||
| 15 | std::string Environment(const char* name); | ||
| 16 | |||
| 17 | template <class T> struct Choice { | ||
| 18 | std::string_view name; | ||
| 19 | T value; | ||
| 20 | }; | ||
| 21 | |||
| 22 | [[noreturn]] void ThrowUnknownChoice(const char* name, std::string_view value, | ||
| 23 | const std::vector<std::string>& names); | ||
| 24 | |||
| 25 | template <class Choices> | ||
| 26 | 89 | auto EnvironmentChoice(const char* name, const Choices& choices) | |
| 27 | -> std::optional<std::remove_cvref_t<decltype(std::begin(choices)->value)>> { | ||
| 28 | 178 | const std::string value = Lowercase(Environment(name)); | |
| 29 | 89 | if (value.empty()) { | |
| 30 | 84 | return std::nullopt; | |
| 31 | } | ||
| 32 | |||
| 33 | 5 | std::vector<std::string> names; | |
| 34 | 18 | for (const auto& choice : choices) { | |
| 35 | 15 | if (choice.name == value) { | |
| 36 | 2 | return choice.value; | |
| 37 | } | ||
| 38 | 13 | names.emplace_back(choice.name); | |
| 39 | } | ||
| 40 | 3 | ThrowUnknownChoice(name, value, names); | |
| 41 | 91 | } | |
| 42 | |||
| 43 | } | ||
| 44 |