logical_and
class template
<functional>
template <class T> struct logical_and;
Logical AND function object class
This class defines function objects for the "and" logical operation (&&).
Generically, function objects are instances of a class with member function operator() defined. This member function allows the object to be used with the same syntax as a regular function call, and therefore it can be used in templates instead of a pointer to a function.
logical_and has its operator() member defined such that it returns true if both its arguments are true using operator&&, and false otherwise.
This class is derived from binary_function and is defined as:
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template <class T> struct logical_and : binary_function <T,T,bool> {
bool operator() (const T& x, const T& y) const
{return x&&y;}
};
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Objects of this class can be used with several standard algorithms (see algorithm).
Members
- T operator() (const T& x, const T& y)
- Member function returning the result of x&&y.
Example
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// logical_and example
#include <iostream>
#include <functional>
#include <algorithm>
using namespace std;
int main () {
bool foo[] = {true,false,true,false};
bool bar[] = {true,true,false,false};
bool result[4];
transform (foo, foo+4, bar, result, logical_and<bool>() );
cout << boolalpha << "Logical AND:\n";
for (int i=0; i<4; i++)
cout << foo[i] << " AND " << bar[i] << " = " << result[i] << "\n";
return 0;
}
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Output:
Logical AND:
true AND true = true
false AND true = false
true AND false = false
false AND false = false
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See also
| logical_or | Logical OR function object class (class template) |
| logical_not | Logical NOT function object class (class template) |
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