std::sort
Defined in header <algorithm>
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(1) | ||
template< class RandomIt > void sort( RandomIt first, RandomIt last ); |
(until C++20) | |
template< class RandomIt > constexpr void sort( RandomIt first, RandomIt last ); |
(since C++20) | |
template< class ExecutionPolicy, class RandomIt > void sort( ExecutionPolicy&& policy, RandomIt first, RandomIt last ); |
(2) | (since C++17) |
(3) | ||
template< class RandomIt, class Compare > void sort( RandomIt first, RandomIt last, Compare comp ); |
(until C++20) | |
template< class RandomIt, class Compare > constexpr void sort( RandomIt first, RandomIt last, Compare comp ); |
(since C++20) | |
template< class ExecutionPolicy, class RandomIt, class Compare > void sort( ExecutionPolicy&& policy, RandomIt first, RandomIt last, Compare comp ); |
(4) | (since C++17) |
Sorts the elements in the range [first, last)
in ascending order. The order of equal elements is not guaranteed to be preserved.
operator<
.comp
.policy
. These overloads do not participate in overload resolution unless std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is trueParameters
first, last | - | the range of elements to sort |
policy | - | the execution policy to use. See execution policy for details. |
comp | - | comparison function object (i.e. an object that satisfies the requirements of Compare) which returns true if the first argument is less than (i.e. is ordered before) the second. The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); While the signature does not need to have const &, the function must not modify the objects passed to it and must be able to accept all values of type (possibly const) |
Type requirements | ||
-RandomIt must meet the requirements of ValueSwappable and LegacyRandomAccessIterator.
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-The type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible.
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-Compare must meet the requirements of Compare.
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Return value
(none)
Complexity
O(N·log(N)), where N = std::distance(first, last) comparisons on average. |
(until C++11) |
O(N·log(N)), where N = std::distance(first, last) comparisons. |
(since C++11) |
Exceptions
The overloads with a template parameter named ExecutionPolicy
report errors as follows:
- If execution of a function invoked as part of the algorithm throws an exception and
ExecutionPolicy
is one of the standard policies, std::terminate is called. For any otherExecutionPolicy
, the behavior is implementation-defined. - If the algorithm fails to allocate memory, std::bad_alloc is thrown.
Example
#include <algorithm> #include <functional> #include <array> #include <iostream> int main() { std::array<int, 10> s = {5, 7, 4, 2, 8, 6, 1, 9, 0, 3}; // sort using the default operator< std::sort(s.begin(), s.end()); for (auto a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a standard library compare function object std::sort(s.begin(), s.end(), std::greater<int>()); for (auto a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a custom function object struct { bool operator()(int a, int b) const { return a < b; } } customLess; std::sort(s.begin(), s.end(), customLess); for (auto a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a lambda expression std::sort(s.begin(), s.end(), [](int a, int b) { return a > b; }); for (auto a : s) { std::cout << a << " "; } std::cout << '\n'; }
Output:
0 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0
See also
sorts the first N elements of a range (function template) | |
sorts a range of elements while preserving order between equal elements (function template) |