Add version utility

rx/include/rx/Version.hpp

@@ -0,0 +1,64 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+#include <string>
+
+namespace rx {
+enum class VersionTag { Draft, RC, Release };
+
+struct Version {
+  std::uint32_t raw{};
+  VersionTag tag{};
+  std::uint32_t tagVersion{};
+  std::uint32_t gitTag{};
+  bool dirty{};
+
+  std::string toString() const {
+    std::string result = std::to_string(raw);
+
+    if (tag == VersionTag::Draft && gitTag != 0) {
+      result += '-';
+      auto value = gitTag;
+      char buf[7];
+      for (int i = 0; i < 7; ++i) {
+        auto digit = value & 0xf;
+        value >>= 4;
+        if (digit >= 10) {
+          buf[i] = 'a' + (digit - 10);
+        } else {
+          buf[i] += '0' + digit;
+        }
+      }
+
+      for (int i = 0; i < 7; ++i) {
+        result += buf[6 - i];
+      }
+    }
+
+    switch (tag) {
+    case VersionTag::Draft:
+      result += " Draft";
+      break;
+    case VersionTag::RC:
+      result += " RC";
+      break;
+    case VersionTag::Release:
+      break;
+    }
+
+    if (tagVersion) {
+      result += std::to_string(tagVersion);
+    }
+
+
+    if (dirty) {
+      result += '+';
+    }
+
+    return result;
+  }
+};
+
+Version getVersion();
+} // namespace rx