Add non-const overload of std::string::data()

Also fix confusion between pointer and _CharT*, so that allocators with
fancy pointers work correctly.

	* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI] (_M_c_str):
	New function.
	(_M_disjunct, basic_string(const basic_string&, size_t)): Use data()
	instead of _M_data().
	(basic_string(const basic_string&, size_t, size_t, const _Alloc&)):
	Likewise.
	(append(const basic_string&)): Likewise.
	(append(const basic_string&, size_type, size_type)): Likewise.
	(assign(const basic_string&, size_type, size_type)): Likewise.
	(insert(size_type, const basic_string&)): Likewise.
	(insert(size_type, const basic_string&, size_type, size_type)):
	Likewise.
	(replace(size_type, size_type, const basic_string&, size_type,
	size_type)): Likewise.
	(replace(__const_iterator, __const_iterator, const basic_string&)):
	Likewise.
	(c_str(), data()): Use c_str() instead of _M_data().
	(data()): Add non-const overload as per LWG 2391 and P0272R1.
	(compare(const basic_string&)): Use data() instead of _M_data().
	[!_GLIBCXX_USE_CXX11_ABI] (data()): Add non-const overload.
	* include/bits/basic_string.tcc [_GLIBCXX_USE_CXX11_ABI] (_M_mutate):
	Pass raw pointers to _S_copy.
	(_M_erase, _M_replace_aux): Pass raw pointers to _S_move and
	_S_assign.
	(find(const _CharT*, size_type, size_type)): Use data instead of
	_M_data().
	* testsuite/21_strings/basic_string/allocator/char/ext_ptr.cc: New.
	* testsuite/21_strings/basic_string/operations/data/char/2.cc: New.
	* testsuite/21_strings/basic_string/operations/data/wchar_t/2.cc: New.

From-SVN: r238291

1 files changed, 10 insertions, 8 deletions

diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
index 2b6644d1c49..1e6d38eb0f3 100644
--- a/libstdc++-v3/include/bits/basic_string.tcc
+++ b/libstdc++-v3/include/bits/basic_string.tcc
@@ -315,14 +315,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       size_type __new_capacity = length() + __len2 - __len1;
       pointer __r = _M_create(__new_capacity, capacity());
+      _CharT* __p = std::__addressof(*__r);
 
       if (__pos)
-	this->_S_copy(__r, _M_data(), __pos);
+	this->_S_copy(__p, _M_c_str(), __pos);
       if (__s && __len2)
-	this->_S_copy(__r + __pos, __s, __len2);
+	this->_S_copy(__p + __pos, __s, __len2);
       if (__how_much)
-	this->_S_copy(__r + __pos + __len2,
-		      _M_data() + __pos + __len1, __how_much);
+	this->_S_copy(__p + __pos + __len2,
+		      _M_c_str() + __pos + __len1, __how_much);
 
       _M_dispose();
       _M_data(__r);
@@ -336,8 +337,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       const size_type __how_much = length() - __pos - __n;
 
+      _CharT* __p = _M_c_str();
       if (__how_much && __n)
-	this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
+	this->_S_move(__p + __pos, __p + __pos + __n, __how_much);
 
       _M_set_length(length() - __n);
     }
@@ -400,7 +402,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       if (__new_size <= this->capacity())
 	{
-	  pointer __p = this->_M_data() + __pos1;
+	  _CharT* __p = this->_M_c_str() + __pos1;
 
 	  const size_type __how_much = __old_size - __pos1 - __n1;
 	  if (__how_much && __n1 != __n2)
@@ -410,7 +412,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	this->_M_mutate(__pos1, __n1, 0, __n2);
 
       if (__n2)
-	this->_S_assign(this->_M_data() + __pos1, __n2, __c);
+	this->_S_assign(this->_M_c_str() + __pos1, __n2, __c);
 
       this->_M_set_length(__new_size);
       return *this;
@@ -1179,7 +1181,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       __glibcxx_requires_string_len(__s, __n);
       const size_type __size = this->size();
-      const _CharT* __data = _M_data();
+      const _CharT* __data = data();
 
       if (__n == 0)
 	return __pos <= __size ? __pos : npos;