std::forward_list<T,Allocator>::sort
void sort(); |
(1) | (since C++11) |
template< class Compare > void sort( Compare comp ); |
(2) | (since C++11) |
Sorts the elements in ascending order. The order of equal elements is preserved. The first version uses operator< to compare the elements, the second version uses the given comparison function comp
.
If an exception is thrown, the order of elements in *this is unspecified.
Parameters
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) |
Return value
(none)
Complexity
Approximately N log N comparisons, where N is the number of elements in the list.
Notes
std::sort requires random access iterators and so cannot be used with forward_list
. This function also differs from std::sort in that it does not require the element type of the forward_list
to be swappable, preserves the values of all iterators, and performs a stable sort.
Example
#include <iostream> #include <functional> #include <forward_list> std::ostream& operator<<(std::ostream& ostr, const std::forward_list<int>& list) { for (auto &i : list) { ostr << " " << i; } return ostr; } int main() { std::forward_list<int> list = { 8,7,5,9,0,1,3,2,6,4 }; std::cout << "before: " << list << "\n"; list.sort(); std::cout << "ascending: " << list << "\n"; list.sort(std::greater<int>()); std::cout << "descending: " << list << "\n"; }
Output:
before: 8 7 5 9 0 1 3 2 6 4 ascending: 0 1 2 3 4 5 6 7 8 9 descending: 9 8 7 6 5 4 3 2 1 0