[vcpkg] Add SemVer and Date versioning schemes

toolsrc/include/vcpkg/versions.h

@@ -6,6 +6,14 @@ namespace vcpkg::Versions
 {
     using Version = VersionT;
 
+    enum class VerComp
+    {
+        unk,
+        lt,
+        eq,
+        gt,
+    };
+
     enum class Scheme
     {
         Relaxed,
@@ -32,6 +40,45 @@ namespace vcpkg::Versions
         std::size_t operator()(const VersionSpec& key) const;
     };
 
+    struct RelaxedVersion
+    {
+        std::string original_string;
+        std::vector<long> version;
+
+        static ExpectedS<RelaxedVersion> from_string(const std::string& str);
+        static RelaxedVersion try_from_string(const std::string& str);
+    };
+
+    struct SemanticVersion
+    {
+        std::string original_string;
+        std::string version_string;
+        std::string prerelease_string;
+
+        std::vector<long> version;
+        std::vector<std::string> identifiers;
+
+        static ExpectedS<SemanticVersion> from_string(const std::string& str);
+        static SemanticVersion try_from_string(const std::string& str);
+    };
+
+    struct DateVersion
+    {
+        std::string original_string;
+        std::string version_string;
+        std::string identifiers_string;
+
+        std::vector<long> identifiers;
+
+        static ExpectedS<DateVersion> from_string(const std::string& str);
+        static DateVersion try_from_string(const std::string& str);
+    };
+
+    VerComp compare(const std::string& a, const std::string& b, Scheme scheme);
+    VerComp compare(const RelaxedVersion& a, const RelaxedVersion& b);
+    VerComp compare(const SemanticVersion& a, const SemanticVersion& b);
+    VerComp compare(const DateVersion& a, const DateVersion& b);
+
     struct Constraint
     {
         enum class Type