в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

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2010-05-25T10:27:25Z

1 версия: Импорт контента...

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==Use a function adaptor in vector==

<source lang="cpp">
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <cstring>
using namespace std;
int main()
{
vector<char *> vectorObject;
vector<char *>::iterator p;
int i;
vectorObject.push_back("One");
vectorObject.push_back("Two");
vectorObject.push_back("Three");
vectorObject.push_back("Four");
vectorObject.push_back("Five");
cout << "Sequence contains:";
for(i = 0; i <vectorObject.size(); i++)
cout << vectorObject[ i ] << " ";
cout << endl;
cout << "Searching sequence for Three.\n";
// use a pointer-to-function adaptor
p = find_if(vectorObject.begin(), vectorObject.end(), not1(bind2nd(ptr_fun(strcmp), "Three")));
if(p != vectorObject.end()) {
cout << "Found.";
cout << "Sequence from that point is:";
do {
cout << *p++ << " ";
} while (p != vectorObject.end());
}
return 0;
}

</source>

==Use a unary function object to determine even/odd.==

<source lang="cpp">
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
class isEven: public unary_function<int, bool> {
public:
result_type operator()(argument_type i)
{
return (result_type) !(i%2);
}
};
int main()
{
vector<int> vectorObject;
int i;
for(i = 1; i < 20; i++)
vectorObject.push_back(i);
cout << "Sequence:";
for(i = 0; i <vectorObject.size(); i++)
cout << vectorObject[ i ] << " ";
cout << endl;
i = count_if(vectorObject.begin(), vectorObject.end(), isEven());
cout << i << " numbers are evenly divisible by 2.";
return 0;
}

</source>

==Use member function reference function adaptor==

<source lang="cpp">
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
class Numbers {
int val;
public:
Numbers() {
val = 0;
}
Numbers(int x) {
val = x;
}
bool showval() {
cout << val << " ";
return true;
}
bool isPrime() {
for(int i = 2; i <= (val/2); i++)
if(!(val%i))
return false;
return true;
}
bool isEven() {
return (bool) !(val % 2);
}
bool isOdd() {
return (bool) (val %2);
}
};
int main()
{
vector<Numbers> vectorObject(10);
vector<Numbers>::iterator end_p;
int i;
for(i = 0; i <10; i++)
vectorObject[ i ] = Numbers(i+1);
cout << "Sequence contains: ";
for_each(vectorObject.begin(), vectorObject.end(), mem_fun_ref(&Numbers::showval));
cout << endl;
// remove the primes
end_p = remove_if(vectorObject.begin(), vectorObject.end(), mem_fun_ref(&Numbers::isPrime));
cout << "Sequence after removing primes: ";
for_each(vectorObject.begin(), end_p, mem_fun_ref(&Numbers::showval));
cout << endl;
for(i = 0; i <10; i++)
vectorObject[ i ] = Numbers(i + 1);

end_p = remove_if(vectorObject.begin(), vectorObject.end(), mem_fun_ref(&Numbers::isEven));
cout << "Sequence after removing even values: ";
for_each(vectorObject.begin(), end_p, mem_fun_ref(&Numbers::showval));
cout << endl;
for(i = 0; i < 10; i++)
vectorObject[ i ] = Numbers(i + 1);
end_p = remove_if(vectorObject.begin(), vectorObject.end(), mem_fun_ref(&Numbers::isOdd));
cout << "Sequence after removing odd values: ";
for_each(vectorObject.begin(), end_p, mem_fun_ref(&Numbers::showval));

return 0;
}

</source>

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в 14:21, 25 мая 2010

Admin: 1 версия: Импорт контента...