NAME¶

std::experimental::ranges::advance - std::experimental::ranges::advance

Synopsis¶

Defined in header <experimental/ranges/iterator>
namespace {
(ranges TS)
constexpr /* unspecified */ advance = /* unspecified */; (customization point
object)
}
Call signature
template< Iterator I >
constexpr void advance(I& i, ranges::difference_type_t<I> (1)
n);
template< Iterator I, Sentinel<I> S > (2)
constexpr void advance(I& i, S bound);
template< Iterator I, Sentinel<I> S >
constexpr ranges::difference_type_t<I> advance(I& i, (3)
ranges::difference_type_t<I> n, S bound);

Advances the iterator i n times, or until bound is reached, whichever comes first.

1) If I models RandomAccessIterator, equivalent to i += n. Otherwise, increments (or
decrements if n is negative) i n times. The behavior is undefined if n is negative
and I does not model BidirectionalIterator.
2) If Assignable<I&, S> is satisfied, equivalent to {{{1}}}.
Otherwise, if [i, bound) does not denote a range, the behavior is undefined.
Otherwise, if SizedSentinel<S, I> is satisfied, equivalent to ranges::advance(i,
bound - i).
Otherwise, increments i until i == bound.
3) If SizedSentinel<S, I> is satisfied, equivalent to ranges::advance(i, bound) if
|n| >= |bound - i|, and ranges::advance(i, n) otherwise.
Otherwise, increments (or decrements if n is negative) i either n times or until i
== bound, whichever comes first.
If n > 0, [i, bound) shall denote a range; if n == 0, either [i, bound) or [bound,
i) shall denote a range; if n < 0, [bound, i) shall denote a range, I and S shall be
the same type, and I must model BidirectionalIterator. Otherwise, the behavior is
undefined.

Customization point objects

The name ranges::advance denotes a customization point object, which is a function
object of a literal Semiregular class type (denoted, for exposition purposes, as
AdvanceT). All instances of AdvanceT are equal. Thus, ranges::advance can be copied
freely and its copies can be used interchangeably.

Given a set of types Args..., if std::declval<Args>()... meet the requirements for
arguments to ranges::advance above, AdvanceT will satisfy ranges::Invocable<const
AdvanceT, Args...>. Otherwise, no function call operator of AdvanceT participates in
overload resolution.

In every translation unit in which ranges::advance is defined, it refers to the same
instance of the customization point object. (This means that it can be used freely
in things like inline functions and function templates without violating the
one-definition rule.)

Return value¶

1-2) (none)
3) The number of increment/decrements not performed due to reaching bound. In other
words, n - M, where M is the distance from the starting position of i to the ending
position and is negative if the ending position is before the starting position.

Example¶

This section is incomplete
Reason: no example

See also¶

advance advances an iterator by given distance
(function template)
returns the distance between an iterator and a sentinel, or between the
distance beginning and the end of a range
(function template)
next increment an iterator
(function template)
prev decrement an iterator
(function template)