std::replace_copy, std::replace_copy_if
From Cppreference
| Defined in header <algorithm>
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| template< class InputIterator, class OutputIterator, class T >
OutputIterator replace_copy( InputIterator first, |
(1) | |
| template< class InputIterator, class OutputIterator, class UnaryPredicate, class T >
OutputIterator replace_copy_if( InputIterator first, |
(2) | |
Copies the all elements from the range [first, last) to another range beginning at d_first replacing all elements satisfying specific criteria with new_value. The first version replaces the elements that are equal to old_value, the second version replaces elements for which predicate p returns true. The source and destination ranges cannot overlap.
Contents |
[edit] Parameters
| first, last | - | the range of elements to copy | |||||||||
| d_first | - | the beginning of the destination range | |||||||||
| old_value | - | the value of elements to replace | |||||||||
| p | - | unary predicate which returns true if the element value should be replaced. The signature of the predicate function should be equivalent to the following:
The signature does not need to have const &, but the function must not modify the objects passed to it. |
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| new_value | - | the value to use as replacement | |||||||||
[edit] Return value
iterator to the element past the last element copied.
[edit] Complexity
Exactly last - first applications of the predicate.
[edit] Equivalent function
| First version |
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template<class InputIterator, class OutputIterator, class T> OutputIterator replace_copy(InputIterator first, InputIterator last, OutputIterator d_first, const T& old_value, const T& new_value) { for (; first != last; ++first) { *d_first++ = (*first == old_value) ? new_value : *first; } return d_first; } |
| Second version |
template<class InputIterator, class OutputIterator, class UnaryPredicate, class T> OutputIterator replace_copy_if(InputIterator first, InputIterator last, OutputIterator d_first, UnaryPredicate p, const T& new_value) { for (; first != last; ++first) { *d_first++ = (p( *first ) ? new_value : *first; } return d_first; } |
[edit] Example
The following copy prints a vector, replacing all values over 5 with 99 on the fly.
#include <algorithm> #include <vector> #include <iostream> #include <iterator> #include <functional> int main() { std::vector<int> v{5, 7, 4, 2, 8, 6, 1, 9, 0, 3}; std::replace_copy_if(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "), [](int n){return n > 5;}, 99); std::cout << '\n'; }
Output:
5 99 4 2 99 99 1 99 0 3
[edit] See also
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removes elements satisfying specific criteria (function template) |
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