Addressing missing test identified by @hultonha

Signed-off-by: Esteban Papp <81431996+amznestebanpapp@users.noreply.github.com>

Code/Framework/AzCore/AzCore/std/string/conversions.h

@@ -70,6 +70,18 @@ namespace AZStd
                 }
             }
 
+            static inline size_t to_string_length(AZStd::wstring_view src)
+            {
+                if constexpr (Size == 2)
+                {
+                    return Utf8::Unchecked::utf16ToUtf8BytesRequired(src.begin(), src.end());
+                }
+                else if constexpr (Size == 4)
+                {
+                    return Utf8::Unchecked::utf32ToUtf8BytesRequired(src.begin(), src.end());
+                }
+            }
+
             template<class Allocator>
             static inline void to_wstring(AZStd::basic_string<wstring::value_type, wstring::traits_type, Allocator>& dest, AZStd::string_view src)
             {
@@ -307,6 +319,11 @@ namespace AZStd
         }
     }
 
+    inline size_t to_string_length(AZStd::wstring_view src)
+    {
+        return Internal::WCharTPlatformConverter<>::to_string_length(src);
+    }
+
     template<class Allocator>
     int stoi(const AZStd::basic_string<wstring::value_type, wstring::traits_type, Allocator>& str, AZStd::size_t* idx = 0, int base = 10)
     {

Code/Framework/AzCore/Platform/Common/WinAPI/AzCore/Utils/Utils_WinAPI.cpp

@@ -43,7 +43,7 @@ namespace AZ
             }
             else
             {
-                size_t utf8PathSize = Utf8::Unchecked::utf16ToUtf8BytesRequired(pathBufferW, pathBufferW + pathLen);
+                size_t utf8PathSize = AZStd::to_string_length({ pathBufferW, pathLen });
                 if (utf8PathSize >= exeStorageSize)
                 {
                     result.m_pathStored = ExecutablePathResult::BufferSizeNotLargeEnough;

Code/Framework/AzCore/Tests/AZStd/String.cpp

@@ -674,6 +674,7 @@ namespace UnitTest
         string str1;
         to_string(str1, wstr);
         AZ_TEST_ASSERT(str1 == "BlaBla 5");
+        EXPECT_EQ(8, to_string_length(wstr));
 
         str1 = string::format("%ls", wstr.c_str());
         AZ_TEST_ASSERT(str1 == "BlaBla 5");
@@ -690,6 +691,11 @@ namespace UnitTest
         char strBuffer[9];
         to_string(strBuffer, 9, wstr1.c_str());
         AZ_TEST_ASSERT(0 == azstricmp(strBuffer, "BLABLA 5"));
+        EXPECT_EQ(8, to_string_length(wstr1));
+
+        // wstring to char with unicode
+        wstring ws1InfinityEscaped = L"Infinity: \u221E"; // escaped
+        EXPECT_EQ(13, to_string_length(ws1InfinityEscaped));
 
         // wchar_t buffer to char buffer
         wchar_t wstrBuffer[9] = L"BLABLA 5";