Adds lib-uuid

Adds a small library to generate UUID values. This library will be used in Sentry error reporting
Replace constructor cast with static_cast


Removes a noexcept sneaked in


Adds documentation and some code review fixes


Fixes doxygen

libraries/lib-uuid/Uuid.h

@@ -0,0 +1,92 @@
+/*!********************************************************************
+
+ Audacity: A Digital Audio Editor
+
+ @file Uuid.h
+ @brief Declare a class to generate and parse UUIDs
+
+ Dmitry Vedenko
+ **********************************************************************/
+
+#pragma once
+
+#include <array>
+#include <cstdint>
+#include <string>
+
+namespace audacity
+{
+
+/*! @brief Utility class that generates and parses UUIDs.
+
+UUIDs are generated using:
+* UuidCreate on Windows,
+* CFUUIDCreate on macOS,
+* libuuid on other systems.
+*/
+class UUID_API Uuid final
+{
+public:
+   using Bytes = std::array<uint8_t, 16>;
+
+   //! Creates a nil UUID
+   Uuid();
+
+   //! Creates UUID from the 16 bytes long array. 
+   explicit Uuid(const Bytes& data) noexcept;
+
+   //! Generate a new UUID
+   static Uuid Generate();
+
+   //! Parses an UUID from the string. 
+   //! This method expects the string to be in
+   //! xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx or
+   //! {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
+   //! formats. 
+   //! This will return nil UUID if parsing fails
+   static Uuid FromString(const std::string& str);
+
+   //! Checks, if the UUID is nil
+   bool IsNil() const noexcept;
+
+   //! Synonymous to !isNil()
+   explicit operator bool() const noexcept;
+
+   // Comparison is performed lexicographically.
+
+   bool operator==(const Uuid& other) const noexcept;
+   bool operator!=(const Uuid& other) const noexcept;
+
+   bool operator>(const Uuid& other) const noexcept;
+   bool operator>=(const Uuid& other) const noexcept;
+
+   bool operator<(const Uuid& other) const noexcept;
+   bool operator<=(const Uuid& other) const noexcept;
+
+   //! Get the 16 bytes long array with the raw UUID data
+   const Bytes& ToBytes() const noexcept;
+   
+   //! Get a string in the xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx format 
+   std::string ToString() const;
+
+   //! Get a string in the xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx format
+   std::string ToHexString() const;
+
+   std::size_t GetHash() const noexcept;
+
+private:
+   Bytes mData;
+};
+
+} // namespace audacity
+
+namespace std
+{
+template <> struct UUID_API hash<audacity::Uuid>
+{
+   std::size_t operator()(const audacity::Uuid& uuid) const noexcept
+   {
+      return uuid.GetHash();
+   }
+};
+} // namespace std