std::remove_copy, std::remove_copy_if - cppreference.com

De cppreference.com

Definido no cabeçalho `<algorithm>`

`template< class InputIt, class OutputIt, class T > OutputIt remove_copy( InputIt first, InputIt last, OutputIt d_first, const T& value );`	(1)

`template< class InputIt, class OutputIt, class UnaryPredicate > OutputIt remove_copy_if( InputIt first, InputIt last, OutputIt d_first, UnaryPredicate p );`	(2)

Copies elements from the range [first, last), to another range beginning at d_first, omitting the elements which satisfy specific criteria. The first version ignores the elements that are equal to value, the second version ignores the elements for which predicate p returns true. Source and destination ranges cannot overlap.

Parâmetros

first, last	-	a gama de elementos para copiar Original: the range of elements to copy The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
d_first	-	the beginning of the destination range.
value	-	the value of the elements not to copy
Type requirements
-`InputIt` must meet the requirements of `InputIterator`.
-`OutputIt` must meet the requirements of `OutputIterator`.

Valor de retorno

Iterador para o elemento passado o último elemento copiado.

Original:

Iterator to the element past the last element copied.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Complexidade

Exatamente last - first aplicações do predicado.

Original:

Exactly last - first applications of the predicate.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Possível implementação

First version
template<class InputIt, class OutputIt, class T> OutputIt remove_copy(InputIt first, InputIt last, OutputIt d_first, const T& value) { for (; first != last; ++first) { if (!(first == value)) { d_first++ = *first; } } return d_first; }
Second version
template<class InputIt, class OutputIt, class UnaryPredicate> OutputIt remove_copy_if(InputIt first, InputIt last, OutputIt d_first, UnaryPredicate p) { for (; first != last; ++first) { if (!p(first)) { d_first++ = *first; } } return d_first; }

First version

template<class InputIt, class OutputIt, class T>
OutputIt remove_copy(InputIt first, InputIt last,
                     OutputIt d_first, const T& value)
{
    for (; first != last; ++first) {
        if (!(*first == value)) {
            *d_first++ = *first;
        }
    }
    return d_first;
}

Second version

template<class InputIt, class OutputIt, class UnaryPredicate>
OutputIt remove_copy_if(InputIt first, InputIt last,
                        OutputIt d_first, UnaryPredicate p)
{
    for (; first != last; ++first) {
        if (!p(*first)) {
            *d_first++ = *first;
        }
    }
    return d_first;
}

Exemplo

The following code outputs a string while erasing the spaces on the fly.

#include <algorithm>
#include <iterator>
#include <string>
#include <iostream>
int main()
{
    std::string str = "Text with some   spaces";
    std::cout << "before: " << str << "\n";

    std::cout << "after:  ";
    std::remove_copy(str.begin(), str.end(),
                     std::ostream_iterator<char>(std::cout), ' ');
    std::cout << '\n';
}

Saída:

before: Text with some   spaces
after:  Textwithsomespaces

Veja também


	remove elementos que satisfazem critérios específicos Original: removes elements satisfying specific criteria The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) [edit]