--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/gcc49/patches/026-basic_string.patch	Wed Dec 16 20:20:50 2015 -0800
@@ -0,0 +1,72 @@
+# Stefan Teleman <[email protected]>
+# 1. Clearer cast not relying on array index -1.
+# 2. Optimization based on initial std::string size and capacity.
+# Internal patch. Not submitted upstream yet.
+--- libstdc++-v3/include/bits/basic_string.h	2015-05-28 12:27:46.000000000 -0400
++++ libstdc++-v3/include/bits/basic_string.h	2015-09-14 01:16:05.666069507 -0400
+@@ -131,6 +131,15 @@
+       typedef std::reverse_iterator<iterator>		    reverse_iterator;
+ 
+     private:
++      // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
++      struct _Alloc_hider : _Alloc
++      {
++	_Alloc_hider(_CharT* __dat, const _Alloc& __a) _GLIBCXX_NOEXCEPT
++	: _Alloc(__a), _M_p(__dat) { }
++
++	_CharT* _M_p; // The actual data.
++      };
++
+       // _Rep: string representation
+       //   Invariants:
+       //   1. String really contains _M_length + 1 characters: due to 21.3.4
+@@ -268,15 +277,6 @@
+ 	_M_clone(const _Alloc&, size_type __res = 0);
+       };
+ 
+-      // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
+-      struct _Alloc_hider : _Alloc
+-      {
+-	_Alloc_hider(_CharT* __dat, const _Alloc& __a) _GLIBCXX_NOEXCEPT
+-	: _Alloc(__a), _M_p(__dat) { }
+-
+-	_CharT* _M_p; // The actual data.
+-      };
+-
+     public:
+       // Data Members (public):
+       // NB: This is an unsigned type, and thus represents the maximum
+@@ -298,7 +298,10 @@
+ 
+       _Rep*
+       _M_rep() const _GLIBCXX_NOEXCEPT
+-      { return &((reinterpret_cast<_Rep*> (_M_data()))[-1]); }
++      {
++        _Rep* __r = static_cast<_Rep*>(reinterpret_cast<void*>(_M_data()));
++        return --__r;
++      }
+ 
+       // For the internal use we have functions similar to `begin'/`end'
+       // but they do not call _M_leak.
+--- libstdc++-v3/include/bits/basic_string.tcc	2014-01-02 17:30:10.000000000 -0500
++++ libstdc++-v3/include/bits/basic_string.tcc	2015-09-14 01:16:09.408163359 -0400
+@@ -575,7 +575,8 @@
+       // malloc implementations that allocate memory blocks rounded up
+       // to a size which is a power of 2).
+       const size_type __pagesize = 4096;
+-      const size_type __malloc_header_size = 4 * sizeof(void*);
++      const size_type __min_capacity = 32;
++      const size_type __malloc_header_size = 8 * sizeof(void*);
+ 
+       // The below implements an exponential growth policy, necessary to
+       // meet amortized linear time requirements of the library: see
+@@ -586,6 +587,9 @@
+       if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
+ 	__capacity = 2 * __old_capacity;
+ 
++      if (__capacity < __min_capacity)
++        __capacity = __min_capacity;
++
+       // NB: Need an array of char_type[__capacity], plus a terminating
+       // null char_type() element, plus enough for the _Rep data structure.
+       // Whew. Seemingly so needy, yet so elemental.