std::replace_copy, std::replace_copy_if
Defined in header
<algorithm>
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template< class InputIt, class OutputIt, class T >
OutputIt replace_copy( InputIt first, InputIt last, OutputIt d_first, |
(1) | |
template< class InputIt, class OutputIt, class UnaryPredicate, class T >
OutputIt replace_copy_if( InputIt first, InputIt last, OutputIt d_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: bool pred(const Type &a); The signature does not need to have const &, but the function must not modify the objects passed to it. |
new_value | - | the value to use as replacement |
Type requirements | ||
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InputIt must meet the requirements of InputIterator .
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OutputIt must meet the requirements of OutputIterator .
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[edit] Return value
Iterator to the element past the last element copied.
[edit] Complexity
Exactly last - first
applications of the predicate.
[edit] Possible implementation
First version |
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template<class InputIt, class OutputIt, class T> OutputIt replace_copy(InputIt first, InputIt last, OutputIt 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 InputIt, class OutputIt, class UnaryPredicate, class T> OutputIt replace_copy_if(InputIt first, InputIt last, OutputIt 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
removes elements satisfying specific criteria (function template) |
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(parallelism TS)
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parallelized version of std::replace_copy (function template) |
(parallelism TS)
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parallelized version of std::replace_copy_if (function template) |