std::is_partitioned
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<metanoindex/>
<tbody> </tbody>| definiert in Header <algorithm>
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template< class InputIt, class UnaryPredicate > bool is_partitioned( InputIt first, InputIt last, UnaryPredicate p ); |
(seit C++11) | |
Versandkosten
true wenn alle Elemente im Bereich [first, last) die das Prädikat erfüllen p vor allen Elementen, die nicht angezeigt werden. Gibt auch true wenn [first, last) ist leer .Original:
Returns
true if all elements in the range [first, last) that satisfy the predicate p appear before all elements that don't. Also returns true if [first, last) is empty.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Parameter
| first, last | - | das Spektrum der Elemente zu überprüfen
Original: the range of elements to check The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| p | - | unary predicate which returns true für die Elemente voraussichtlich in dem Anfang des Bereichs gefunden werden . Original: for the elements expected to be found in the beginning of the range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. The signature of the predicate function should be equivalent to the following:
The signature does not need to have |
| Type requirements | ||
-InputIt must meet the requirements of InputIterator.
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Rückgabewert
true wenn der Bereich [first, last) leer ist oder von p partitioniert. false sonst .Original:
true if the range [first, last) is empty or is partitioned by p. false otherwise.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Komplexität
An den meisten
std::distance(first, last) Anwendungen p .Original:
At most
std::distance(first, last) applications of p.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Mögliche Implementierung
template< class InputIt, class UnaryPredicate >
bool is_partitioned(InputIt first, InputIt last, UnaryPredicate p)
{
for (; first != last; ++first)
if (!p(*first))
break;
for (; first != last; ++first)
if (p(*first))
return false;
return true;
}
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Beispiel
#include <algorithm>
#include <array>
#include <iostream>
int main()
{
std::array<int, 9> v = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
auto is_even = [](int i){ return i % 2 == 0; };
std::cout.setf(std::ios_base::boolalpha);
std::cout << std::is_partitioned(v.begin(), v.end(), is_even) << ' ';
std::partition(v.begin(), v.end(), is_even);
std::cout << std::is_partitioned(v.begin(), v.end(), is_even) << ' ';
std::reverse(v.begin(), v.end());
std::cout << std::is_partitioned(v.begin(), v.end(), is_even);
}
Output:
false true false