C++ concepts: RandomAccessIterator
From cppreference.com
                    
                                        
                    
                    
                                                            
                    A RandomAccessIterator is a BidirectionalIterator that can be moved to point to any element in constant time.
A pointer to an element of an array satisfies all requirements of RandomAccessIterator
[edit] Requirements
The type It satisfies RandomAccessIterator if
-  The type ItsatisfiesBidirectionalIterator
And, given
-  value_type, the type denoted by std::iterator_traits<It>::value_type
-  difference_type, the type denoted by std::iterator_traits<It>::difference_type
-  reference, the type denoted by std::iterator_traits<It>::reference
-  i,a,b, objects of typeItorconst It
-  r, a value of typeIt&
-  n, an integer of typedifference_type
The following expressions must be valid and have their specified effects
| Expression | Return type | Operational semantics | Notes | 
|---|---|---|---|
| r += n | It& | difference_type m = n; if (m >= 0) while (m--) ++r; | 
 | 
| a + n n + a | It | It temp = a; return temp += n; | 
 | 
| r -= n | It& | return r += -n; | |
| i - n | It | It temp = i; return temp -= n; | |
| b - a | difference_type | return n; | Precondition: 
 Postcondition: 
 | 
| i[n] | convertible to reference | *(i + n) | |
| a < b | contextually convertible to bool | b - a > 0 | Strict total ordering relation: 
 | 
| a > b | contextually convertible to bool | b < a | Total ordering relation opposite to a < b | 
| a >= b | contextually convertible to bool | !(a < b) | |
| a <= b | contextually convertible to bool | !(a > b) | 
The above rules imply that RandomAccessIterator also implements LessThanComparable.
A mutable RandomAccessIterator is a RandomAccessIterator that additionally satisfies the OutputIterator requirements.


