std::stable_partition - cppreference.com (original) (raw)

1. Reorders the elements in the range [first, last) in such a way that all elements for which the predicate p returns true precede the elements for which predicate p returns false. Relative order of the elements is preserved.

2. Same as (1), but executed according to policy.

This overload participates in overload resolution only if all following conditions are satisfied:

If any of the following conditions is satisfied, the behavior is undefined:

Contents

• 1 Parameters
• 2 Return value
• 3 Complexity
• 4 Exceptions
• 5 Notes
• 6 Example
• 7 Defect reports
• 8 See also

[edit] Parameters

[edit] Return value

Iterator to the first element of the second group.

[edit] Complexity

Given \(\scriptsize N\)N as std::distance(first, last):

1. Exactly \(\scriptsize N\)N applications of p.

\(\scriptsize O(N)\)O(N) swaps if there is enough extra memory, otherwise at most \(\scriptsize N \cdot log_{2}(N)\)N⋅log2(N) swaps.

1. \(\scriptsize O(N)\)O(N) applications of p.

\(\scriptsize N \cdot log(N)\)N⋅log(N) swaps.

[edit] Exceptions

The overload with a template parameter named ExecutionPolicy reports 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 other ExecutionPolicy, the behavior is implementation-defined.
• If the algorithm fails to allocate memory, std::bad_alloc is thrown.

[edit] Notes

This function attempts to allocate a temporary buffer. If the allocation fails, the less efficient algorithm is chosen.

Implementations in libc++ and libstdc++ also accept ranges denoted by LegacyForwardIterators as an extension.

[edit] Example

#include #include #include   int main() { std::vector v{0, 0, 3, -1, 2, 4, 5, 0, 7}; std::stable_partition(v.begin(), v.end(), [](int n) { return n > 0; }); for (int n : v) std::cout << n << ' '; std::cout << '\n'; }

Output:

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit] See also