chore: import upstream snapshot with attribution

2026-07-13 12:36:49 +08:00
commit e7ae061fa2
2645 changed files with 497412 additions and 0 deletions
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2022 Axel Waggershauser
+ */
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include <string>
+#include <cstdint>
+
+namespace ZXing {
+
+/**
+ * @brief The Error class is a value type for the error() member of @Barcode
+ *
+ * The use-case of this class is to communicate whether or not a particular Barcode
+ * symbol is in error. It is (primarily) not meant to be thrown as an exception and
+ * therefore not derived from std::exception. The library code may throw (and catch!)
+ * objects of this class as a convenient means of flow control (c++23's std::expected
+ * will allow to replace those use-cases with something similarly convenient). In
+ * those situations, the author is advised to make sure any thrown Error object is
+ * caught before leaking into user/wrapper code, i.e. the functions of the public
+ * API should be considered `noexcept` with respect to this class.
+ *
+ * Looking at the implementation of std::runtime_exception, it might actually be of
+ * interest to replace the std::string msg member with a std::runtime_exception base
+ * class, thereby reducing sizeof(Error) by 16 bytes. This would be a breaking ABI
+ * change and would therefore have to wait for release 3.0. (TODO)
+ */
+
+class Error
+{
+public:
+	enum class Type : uint8_t { None, Format, Checksum, Unsupported };
+	Type type() const noexcept { return _type; }
+	const std::string& msg() const noexcept { return _msg; }
+	explicit operator bool() const noexcept { return _type != Type::None; }
+
+	std::string location() const;
+
+	Error() = default;
+	Error(Type type, std::string msg = {}) : _msg(std::move(msg)), _type(type) {}
+	Error(const char* file, short line, Type type, std::string msg = {}) : _msg(std::move(msg)), _file(file), _line(line), _type(type) {}
+
+	static constexpr auto Format = Type::Format;
+	static constexpr auto Checksum = Type::Checksum;
+	static constexpr auto Unsupported = Type::Unsupported;
+
+	inline bool operator==(const Error& o) const noexcept
+	{
+		return _type == o._type && _msg == o._msg && _file == o._file && _line == o._line;
+	}
+	inline bool operator!=(const Error& o) const noexcept { return !(*this == o); }
+
+protected:
+	std::string _msg;
+	const char* _file = nullptr;
+	short _line = -1;
+	Type _type = Type::None;
+};
+
+inline bool operator==(const Error& e, Error::Type t) noexcept { return e.type() == t; }
+inline bool operator!=(const Error& e, Error::Type t) noexcept { return !(e == t); }
+inline bool operator==(Error::Type t, const Error& e) noexcept { return e.type() == t; }
+inline bool operator!=(Error::Type t, const Error& e) noexcept { return !(t == e); }
+
+#define FormatError(...) Error(__FILE__, __LINE__, Error::Format, std::string(__VA_ARGS__))
+#define ChecksumError(...) Error(__FILE__, __LINE__, Error::Checksum, std::string(__VA_ARGS__))
+#define UnsupportedError(...) Error(__FILE__, __LINE__, Error::Unsupported, std::string(__VA_ARGS__))
+
+std::string ToString(const Error& e);
+
+}