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Constructors & Destructors
| Operation | Effect |
|---|---|
vector<Elem> c | Default constructor; creates an empty vector without any elements |
vector<Elem> c(c2) | Copy constructor; creates a new vector as a copy of c2 (all elements are copied) |
vector<Elem> c = c2 | Copy constructor; creates a new vector as a copy of c2 (all elements are copied) |
vector<Elem> c(rv) | Move constructor; creates a new vector, taking the contents of the r value rv (since C++11) |
vector<Elem> c = rv | Move constructor; creates a new vector, taking the contents of the r value rv (since C++11 |
vector<Elem> c(n) | Creates a vector with n elements created by the default constructor |
vector<Elem> c(n, elem) | Creates a vector initialized with n copies of element elem |
vector<Elem> c(beg, end) | Creates a vector initialized with the elements of the range [beg, end) |
vector<Elem> c(initlist) | Creates a vector initialized with the elements of initializer list initlist (since C++11) |
vector<Elem> c = initlist | Creates a vector initialized with the elements of initializer list initlist (since C++11) |
c.~vector() | Destroys all elements and frees the memory |
Non-modifying Operations
| Operation | Effect |
|---|---|
c.empty() | Returns whether the container is empty (equivalent to size()==0 but might be faster) |
c.size() | Returns the current number of elements |
c.max_size() | Returns the maximum number of elements possible |
c.capacity() | Returns the maximum possible number of elements without reallocation |
c.reserve(num) | Enlarges capacity, if not enough yet |
c.shrink_to_fit() | Request to reduce capacity to fit number of elements (since C++11) |
c1 == c2 | Returns whether c1 is equal to c2 (calls == for elements) |
c1 != c2 | Returns whether c1 is not equal to c2; !(c1==c2) |
c1 < c2 | Returns whether c1 is less than c2 |
c1 > c2 | Returns whether c1 is greater than c2; c2>c1 |
c1 <= c2 | Returns whether c1 is less than or equal to c2; !(c2<c1) |
c1 >= c2 | Returns whether c1 is greater than or equal to c2; !(c1<c2) |
Assignments
| Operation | Effect |
|---|---|
c = c2 | Assigns all elements of c2 to c |
c = initlist | Assigns all elements of the initializer list initlist to c (since C++11) |
c.assign(n, elem) | Assigns n copies of element elem |
c.assign(beg, end) | Assigns the elements of the range [beg, end) |
c.assign(initlist) | Assigns all the elements of the initializer list initlist |
c1.swap(c2) | Swaps the data of c1 and c2 |
swap(c1, c2) | Swaps the data of c1 and c2 |
Element Access
| Operation | Effect |
|---|---|
c[idx] | Returns the element with index idx (no range checking) |
c.at(idx) | Returns the element with index idx (throws range-error exception if idx is out of range) |
c.front() | Returns the first element (no check whether a first element exists) |
c.back() | Returns the last element (no check whether a last element exists) |
Iterator Operations
| Operation | Effect |
|---|---|
c.begin() | Returns a random-access iterator for the first element |
c.end() | Returns a random-access iterator for the position after the last element |
c.cbegin() | Returns a constant random-access iterator for the element (since C++11) |
c.cend() | Returns a constant random-access iterator for the position after the last element (since C++11) |
c.rbegin() | Returns a reverse iterator for the first element of a reverse iteration |
c.rend() | Returns a reverse iterator for the position after the last element of a reverse iteration |
c.crbegin() | Returns a constant reverse iterator for the first element of a reverse iteration (since C++11) |
c.rend() | Returns a constant reverse iterator for the position after the last element of a reverse iteration (since C++11) |
Insert & Remove
| Operation | Effect |
|---|---|
c.push_back(elem) | Appends a copy of elem at the end |
c.pop_back() | Removes the last element (does not return it) |
c.insert(pos, elem) | Inserts a copy of elem before iterator position pos and returns the position of the new element |
c.insert(pos, n, elem) | Inserts n copies of elem before iterator position pos and returns the position of the first new element (or pos if there is no new element) |
c.insert(pos, beg, end) | Inserts a copy of all elements of the range [beg, end) before iterator position pos and returns the position of the first new element (or pos if there is no new element) |
c.insert(pos, initlist) | Inserts a copy of all elements of the initializer list initlist before iterator position pos and returns the position of the first new element (or pos if there is no new element; since C++11) |
c.emplace(pos, args, ...) | Inserts a copy of an element initialized with args before iterator position pos and returns the position of the new element (since C++11) |
c.emplace_back(args, ...) | Appends a copy of an element initialized with args at the end (returns nothing; since C++11) |
c.erase(pos) | Removes the element at iterator position pos and returns the position of the next element |
c.erase(beg, end) | Removes elements of the range [beg, end) and returns the of the next element |
c.resize(num) | Changes the number of elements to num (if size() grows new elements are created by their default constructor) |
c.resize(num, elem) | Changes the number of elements to num (if size() grows new elements are copies of elem) |
c.clear() | Removes all elements (empties the container) |