Is char a Signed Type

std::numeric_limits<char>::is_signed tells you if char is a signed type or not.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 61-62.

NULL

A C NULL is (void*)0, a C++ NULL is 0.

Reference: The C++ Standard Library: A Tutorial and Reference by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 71.

atexit() Function

Functions registered by atexit() are executed in reverse order when a program ends.

If exit() is called, these functions are still called.

If abort() is called, these functions are not called.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 71.

Tertiary Operator

Given:

    int x = 0; 
    int y = 0; 

Then:

    (1 ? x : y) = 4; 

Sets x to 4.

String's push_back() Member Function

The string container has a push_back() member function.

Reference: The C++ Standard Library by Nicolai Josuttis. Addison-Wesley, 1999, p. 81.

Incrementing an Insert Iterator

Incrementing an insert iterator is a NO OP.

Reference: The C++ Standard Library by Nicolai M. Josuttiis. Addison-Wesley, 1999, p. 104.

Vector at() Function

If you have a vector v; v.at(10) will do range checking, while v[10] will not.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 152.

POD Data

Every ordinary C structure is POD data (Plain Old Data).

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 156.

Vector Reallocations

When a vector is forced to perform a reallocation, all of its elements must to be copied. For a deque (pronounced "deck"), it is not always necessary that all of its elements are copied during a reallocation. This is because a deque does not have to be stored contiguously as in the case of a vector.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 161.

capacity() and reserve()

Vector and string provide the functions capacity() and reserve(). They are the only STL containers that have these functions.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 163.

at() and operator[]() Functions

Vectors and deques provide the at() and operator[]() functions. Having these functions happens to correspond with containers that have Random Access Iterators, with one exception. map has operator[](), but does not have a random access iterator. Map's operator[]() does not execute in constant time, O(1); whereas containers with random access iterators are able to execute in constant time.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 162.

List front() and back()

On a list, el, if the element el.front() exists, then el.back() also exists.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 168.

C++ Containers

C++ set, multiset, list, map, and multimap are node-based containers. The other kind of container is the array-based container. String, vector, and deque are arry-based containers.

Node-based iterators only become invalid when the item they point to is erased.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 185.

Random Access Iterators

Pointers are random access iterators.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 218.

Iterator Categories

Vector, deque, and string have random access iterators; list, set, multiset, map and multimap have bidirectional iterators.

The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 239.

Reverse Iterators

All of the following have reverse iterators: vector, deque, list, set, multiset, map, multimap, and string.

Reference: The C++ Standard Library by Nicolai M. Josuttis. Addison-Wesley, 1999, p. 240.