3 files changed, 20 insertions, 10 deletions
diff --git a/core/fxcrt/fx_basic_bstring.cpp b/core/fxcrt/fx_basic_bstring.cpp
index 0b9d9873d8..c5979a7466 100644
--- a/core/fxcrt/fx_basic_bstring.cpp
+++ b/core/fxcrt/fx_basic_bstring.cpp
@@ -216,6 +216,15 @@ bool CFX_ByteString::operator==(const CFX_ByteString& other) const {
                       m_pData->m_nDataLength) == 0;
 }
 
+bool CFX_ByteString::operator<(const CFX_ByteString& str) const {
+  if (m_pData == str.m_pData)
+    return false;
+
+  int result = FXSYS_memcmp(c_str(), str.c_str(),
+                            std::min(GetLength(), str.GetLength()));
+  return result < 0 || (result == 0 && GetLength() < str.GetLength());
+}
+
 bool CFX_ByteString::EqualNoCase(const CFX_ByteStringC& str) const {
   if (!m_pData)
     return str.IsEmpty();
diff --git a/core/fxcrt/fx_basic_wstring.cpp b/core/fxcrt/fx_basic_wstring.cpp
index 88fc588947..29e915f30c 100644
--- a/core/fxcrt/fx_basic_wstring.cpp
+++ b/core/fxcrt/fx_basic_wstring.cpp
@@ -194,6 +194,15 @@ bool CFX_WideString::operator==(const CFX_WideString& other) const {
                  m_pData->m_nDataLength) == 0;
 }
 
+bool CFX_WideString::operator<(const CFX_WideString& str) const {
+  if (m_pData == str.m_pData)
+    return false;
+
+  int result =
+      wmemcmp(c_str(), str.c_str(), std::min(GetLength(), str.GetLength()));
+  return result < 0 || (result == 0 && GetLength() < str.GetLength());
+}
+
 void CFX_WideString::AssignCopy(const FX_WCHAR* pSrcData, FX_STRSIZE nSrcLen) {
   AllocBeforeWrite(nSrcLen);
   m_pData->CopyContents(pSrcData, nSrcLen);
diff --git a/core/fxcrt/include/fx_string.h b/core/fxcrt/include/fx_string.h
index c1bd82dd74..48378586d3 100644
--- a/core/fxcrt/include/fx_string.h
+++ b/core/fxcrt/include/fx_string.h
@@ -88,11 +88,7 @@ class CFX_ByteString {
     return !(*this == other);
   }
 
-  bool operator<(const CFX_ByteString& str) const {
-    int result = FXSYS_memcmp(c_str(), str.c_str(),
-                              std::min(GetLength(), str.GetLength()));
-    return result < 0 || (result == 0 && GetLength() < str.GetLength());
-  }
+  bool operator<(const CFX_ByteString& str) const;
 
   const CFX_ByteString& operator=(const FX_CHAR* str);
   const CFX_ByteString& operator=(const CFX_ByteStringC& bstrc);
@@ -295,11 +291,7 @@ class CFX_WideString {
     return !(*this == other);
   }
 
-  bool operator<(const CFX_WideString& str) const {
-    int result =
-        wmemcmp(c_str(), str.c_str(), std::min(GetLength(), str.GetLength()));
-    return result < 0 || (result == 0 && GetLength() < str.GetLength());
-  }
+  bool operator<(const CFX_WideString& str) const;
 
   FX_WCHAR GetAt(FX_STRSIZE nIndex) const {
     return m_pData ? m_pData->m_String[nIndex] : 0;