24 Strings library [strings]

24.3 String classes [string.classes]

24.3.2 Class template basic_­string [basic.string]

24.3.2.1 basic_­string general requirements [string.require]

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.
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].
In every specialization basic_­string<charT, traits, Allocator>, the type traits shall satisfy the character traits requirements ([char.traits]), and the type traits​::​char_­type shall name the same type as charT.
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.227
  • Calling non-const member functions, except operator[], at, data, front, back, begin, rbegin, end, and rend.
For example, as an argument to non-member functions swap(), operator>>(), and getline(), or as an argument to basic_­string​::​swap().