Exceptions, with emphasis on C++11 enhancements. Links:

• cppreference.com "Exceptions"
  • throw-expression
  • try-catch block
  • function-try-block
  • noexcept specifier
  • noexcept operator
  • Dynamic exception specification (until C++17)

• Terminate the program.
• Return an error value.
• Return a legal value and leave the program in an “error state” (errno).
• Call an error-handler routine.

C++ standard library provides one of the following guarantees for every library operation:

• basic for all operations: The basic invariants of all objects are maintained, and no resources, such as memory, are leaked. In particular, the basic invariants of every built-in and standard-library type guarantee that you can destroy an object or assign to it after every standard-library operation (§iso.17.6.3.1).
• strong for key operations: in addition to providing the basic guarantee, either the operation succeeds, or it has no effect. This guarantee is provided for key operations, such as push_back(), single-element insert() on a list, and uninitialized_copy().
• nothrow for some operations: in addition to providing the basic guarantee, some operations are guaranteed not to throw an exception. This guarantee is provided for a few simple operations, such as swap() of two containers and pop_back().