Add iterators for Byte/WideStringCs.

Change-Id: I40ec07c0da54bcf36c83fa26ff457cd4b98a91cf
Reviewed-on: https://pdfium-review.googlesource.com/4261
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/core/fxcrt/cfx_widestring.h b/core/fxcrt/cfx_widestring.h
index 52cd65a2b7..fd3c92a15e 100644
--- a/core/fxcrt/cfx_widestring.h
+++ b/core/fxcrt/cfx_widestring.h
@@ -23,6 +23,7 @@ class CFX_ByteString;
 class CFX_WideString {
  public:
   using CharType = wchar_t;
+  using const_iterator = const CharType*;
 
   CFX_WideString();
   CFX_WideString(const CFX_WideString& other);
@@ -61,6 +62,12 @@ class CFX_WideString {
     return CFX_WideStringC(c_str(), GetLength());
   }
 
+  // Note: Any subsequent modification of |this| will invalidate iterators.
+  const_iterator begin() const { return m_pData ? m_pData->m_String : nullptr; }
+  const_iterator end() const {
+    return m_pData ? m_pData->m_String + m_pData->m_nDataLength : nullptr;
+  }
+
   void clear() { m_pData.Reset(); }
 
   FX_STRSIZE GetLength() const { return m_pData ? m_pData->m_nDataLength : 0; }