If any operation would cause size() to exceed max_size(), that operation shall throw an exception object of type length_error.
If any member function or operator of basic_string throws an exception, that function or operator shall have no other effect.
No erase() or pop_back() member function shall throw any exceptions.
In every specialization basic_string<charT, traits, Allocator>, the type allocator_traits<Allocator>::value_type shall name the same type as charT. Every object of type basic_string<charT, traits, Allocator> shall use an object of type Allocator to allocate and free storage for the contained charT objects as needed. The Allocator object used shall be obtained as described in [container.requirements.general].
The char-like objects in a basic_string object shall be stored contiguously. That is, for any basic_string object s, the identity &*(s.begin() + n) == &*s.begin() + n shall hold for all values of n such that 0 <= n < s.size().
References, pointers, and iterators referring to the elements of a basic_string sequence may be invalidated by the following uses of that basic_string object:
as an argument to any standard library function taking a reference to non-const basic_string as an argument.235
Calling non-const member functions, except operator, at, front, back, begin, rbegin, end, and rend.