37 lines
1.6 KiB
C++
37 lines
1.6 KiB
C++
#pragma once
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#include <algorithm>
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#include <cassert>
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#include <string>
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#include <optional>
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namespace mbgl {
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template <typename T>
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class Enum {
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public:
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using Type = T;
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static const char * toString(T);
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static std::optional<T> toEnum(const std::string&);
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};
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#define MBGL_DEFINE_ENUM(T, ...) \
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\
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static const constexpr std::pair<const T, const char *> T##_names[] = __VA_ARGS__; \
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\
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template <> \
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const char * Enum<T>::toString(T t) { \
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auto it = std::find_if(std::begin(T##_names), std::end(T##_names), \
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[&] (const auto& v) { return t == v.first; }); \
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assert(it != std::end(T##_names)); return it->second; \
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} \
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\
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template <> \
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std::optional<T> Enum<T>::toEnum(const std::string& s) { \
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auto it = std::find_if(std::begin(T##_names), std::end(T##_names), \
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[&] (const auto& v) { return s == v.second; }); \
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return it == std::end(T##_names) ? std::optional<T>() : it->first; \
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}
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} // namespace mbgl
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