A ReversibleContainer is a Container that has iterators that meet the requirements of either LegacyBidirectionalIterator or LegacyRandomAccessIterator. Such iterators allow a ReversibleContainer to be iterated over in reverse.
X | Container type |
T | Element type |
a | Objects of type X |
expression | return type | conditions | complexity |
---|---|---|---|
X::reverse_iterator | iterator type whose value type is T | reverse_iterator<iterator> | compile time |
X::const_reverse_iterator | constant iterator type whose value type is T | reverse_iterator<const_iterator> | compile time |
expression | return type | conditions | complexity |
---|---|---|---|
a.rbegin() | reverse_iterator ; const_reverse_iterator for constant a | reverse_iterator(end()) | constant |
a.rend() | reverse_iterator ; const_reverse_iterator for constant a | reverse_iterator(begin()) | constant |
a.crbegin() | const_reverse_iterator | const_cast<X const&>(a).rbegin() | constant |
a.crend() | const_reverse_iterator | const_cast<X const&>(a).rend() | constant |
The following example iterates over a vector (which has random-access iterators) in reverse.
#include <vector> #include <iostream> int main() { std::vector<int> v = {3, 1, 4, 1, 5, 9}; for(std::vector<int>::reverse_iterator i = v.rbegin(); i != v.rend(); ++i) { std::cout << *i << '\n'; } }
Output:
9 5 1 4 1 3
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