Remove GetAt from string classes

This method duplicates the behaviour of the const [] operator and
doesn't offer any additional safety. Folding them into one
implementation.

SetAt is retained, since implementing the non-const [] operator to
replace SetAt has potential performance concerns. Specifically many
non-obvious cases of reading an element using [] will cause a realloc
& copy.

BUG=pdfium:860

Change-Id: I3ef5e5e5a15376f040256b646eb0d90636e24b67
Reviewed-on: https://pdfium-review.googlesource.com/10870
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/core/fxcrt/cfx_string_c_template.h b/core/fxcrt/cfx_string_c_template.h
index bc0fe1e0a0..99948e90a0 100644
--- a/core/fxcrt/cfx_string_c_template.h
+++ b/core/fxcrt/cfx_string_c_template.h
@@ -119,12 +119,12 @@ class CFX_StringCTemplate {
   FX_STRSIZE GetLength() const { return m_Length; }
   bool IsEmpty() const { return m_Length == 0; }
 
-  UnsignedType GetAt(FX_STRSIZE index) const {
+  const UnsignedType& operator[](const FX_STRSIZE index) const {
     ASSERT(index >= 0 && index < GetLength());
     return m_Ptr.Get()[index];
   }
 
-  CharType CharAt(FX_STRSIZE index) const {
+  const CharType CharAt(const FX_STRSIZE index) const {
     ASSERT(index >= 0 && index < GetLength());
     return static_cast<CharType>(m_Ptr.Get()[index]);
   }
@@ -164,8 +164,6 @@ class CFX_StringCTemplate {
     return CFX_StringCTemplate(m_Ptr.Get() + m_Length - count, count);
   }
 
-  UnsignedType operator[](FX_STRSIZE index) const { return GetAt(index); }
-
   bool operator<(const CFX_StringCTemplate& that) const {
     int result = FXSYS_cmp(reinterpret_cast<const CharType*>(m_Ptr.Get()),
                            reinterpret_cast<const CharType*>(that.m_Ptr.Get()),