Annex C (informative) Compatibility [diff]

C.4 C++ and ISO C++ 2014 [diff.cpp14]

C.4.10 Clause [strings]: strings library [diff.cpp14.string]

[basic.string]
Change: Non-const .data() member added.
Rationale: The lack of a non-const .data() differed from the similar member of std​::​vector. This change regularizes behavior for this International Standard.
Effect on original feature: Overloaded functions which have differing code paths for char* and const char* arguments will execute differently when called with a non-const string's .data() member in this International Standard.

int f(char *) = delete;
int f(const char *);
string s;
int x = f(s.data()); // ill-formed; previously well-formed