Add support for simple empty StringView.

src/String/StringView.cpp

@@ -4,4 +4,7 @@
 namespace ArbUt {
     std::shared_ptr<__ConstStringCharHolder> StringView::__emptyString =
         std::make_shared<__ConstStringCharHolder>("", 0);
+
+    static StringView __empty;
+    const StringView& StringView::Empty() { return __empty; }
 }

src/String/StringView.hpp

@@ -86,6 +86,8 @@ namespace ArbUt {
         CalculateHash(const std::string_view& val) noexcept {
             return Hash(val.data());
         }
+
+        static const StringView& Empty();
     };
 }
 

tests/StringViewTests.cpp

@@ -76,4 +76,9 @@ TEST_CASE("Out of scope char* doesn't lose reference", "[Utilities]") {
     REQUIRE(strcmp(val.c_str(), "foobar") == 0);
 }
 
+TEST_CASE("Get Empty String", "[Utilities]") {
+    REQUIRE(ArbUt::StringView::Empty() == ""_cnc);
+}
+
+
 #endif