std::ranges::concat_view<Views...>::iterator<Const>::satisfy, prev, advance-fwd, advance-bwd
The following exposition-only member function templates simplify the description.
Each helper function template has a non-type template parameter of type std::size_t.
- If the name of the template parameter is N, the template argument is always
it_
.index() - If the name of the template parameter is I, the template argument can be any std::size_t value in
[
0,
sizeof...(Views))
However, the template argument might not be a compile-time constant, therefore the actual effect of
helper
<non_const>(/* arguments */)
is similar to
if (non_const == 0)
helper
<
0
>
(
/* arguments */
)
;
else if (non_const == 1)
helper
<
1
>
(
/* arguments */
)
;
/* other indices */
else
if
(non_const ==
(sizeof...(Views)
-
1
)
)
helper
<sizeof...(Views)
-
1
>
(
/* arguments */
)
;
Helper templates
Mini helper templates
template
<
std::size_t N >
constexpr auto /*get-iter*/ ( ) ; |
(1) | (exposition only*) |
template
<
std::size_t I >
constexpr auto /*get-view*/ ( ) ; |
(2) | (exposition only*) |
template
<
std::size_t I >
constexpr auto /*get-begin*/ ( ) ; |
(3) | (exposition only*) |
template
<
std::size_t I >
constexpr auto /*get-end*/ ( ) ; |
(4) | (exposition only*) |
template
<
std::size_t N >
constexpr auto /*to-underlying-diff-type*/ ( difference_type value ) ; |
(5) | (exposition only*) |
The mini helper templates simplify the description of the main helper templates and member functions. They are not included in the C++ standard documents.
it_
.concat_view
.concat_view
.get-view
<I>())
concat_view
.get-view
<I>())
base-iter
>>>(value)
std::ranges::concat_view::iterator::satisfy<N>
template
<
std::size_t N >
constexpr void /*satisfy*/ ( ) ; |
(exposition only*) | |
Adjusts the current (global) position of it_
.
std::ranges::concat_view::iterator::prev<N>
template
< size_t N >
constexpr void /*prev*/ ( ) ; |
(exposition only*) | |
Moves it_
to the previous (global) position.
std::ranges::concat_view::iterator::advance-fwd<N>
template
< size_t N >
constexpr void /*advance-fwd*/( difference_type offset, |
(exposition only*) | |
Advances the current (global) position step steps forward.
- If N is sizeof...(Views) - 1, equivalent to
get-iter
<N>() +=to-underlying-diff-type
(steps); - Otherwise, equivalent to
auto n_size =
ranges::distance
(
get-view
<N>()));
if (offset + steps < n_size)
get-iter
<N>() +=to-underlying-diff-type
(steps);
else
{
it_
.template emplace<N + 1>(get-begin
<N + 1 > ( ) ) ;
advance-fwd
<N + 1 > ( 0, offset + steps - n_size) ;
}
Parameters
offset | - | the offset of the current (global) position from the beginning of range it_ currently refers into
|
steps | - | the number of steps to advance forward |
std::ranges::concat_view::iterator::advance-bwd<N>
template
< size_t N >
constexpr void /*advance-bwd*/( difference_type offset, |
(exposition only*) | |
Advances the current (global) position steps steps backward.
- If N is 0, equivalent to
get-iter
<N>() -=to-underlying-diff-type
(steps); - Otherwise, equivalent to
if (offset >= steps)
get-iter
<N>() -=to-underlying-diff-type
(steps);
else
{
auto prev_size = ranges::distance (
get-view
<N - 1 > ( ) ) ;
it_
.template emplace<N - 1>(get-end
<N - 1 > ( ) ) ;
advance-bwd
<N - 1 > (prev_size, steps - offset) ;
}
Parameters
offset | - | the offset of the current (global) position from the beginning of range it_ currently refers into
|
steps | - | the number of steps to advance backward |