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
.
The type It
satisfies RandomAccessIterator
if.
It
satisfies BidirectionalIterator
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 type It
or const It
r
, a value of type It&
n
, an integer of type difference_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; else while (m++) r; return r; 


a + n

It 
It temp = a; return temp += n; 


r = n  It& 
return r += n;  The absolute value of n must be within the range of representable values of difference_type .  
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.
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