equal_to (STL/CLR)

Article
06/05/2017

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The latest version of this topic can be found at equal_to (STL/CLR).

The template class describes a functor that, when called, returns true only if the first argument is equal to the second. You use it specify a function object in terms of its argument type.

Syntax

template<typename Arg>  
    ref class equal_to  
    { // wrap operator()  
public:  
    typedef Arg first_argument_type;  
    typedef Arg second_argument_type;  
    typedef bool result_type;  
    typedef Microsoft::VisualC::StlClr::BinaryDelegate<  
        first_argument_type, second_argument_type, result_type>  
        delegate_type;  
  
    equal_to();  
    equal_to(equal_to<Arg>% right);  
  
    result_type operator()(first_argument_type left,  
        second_argument_type right);  
    operator delegate_type^();  
    };

Parameters

Arg
The type of the arguments.

Member Functions

Type Definition	Description
delegate_type	The type of the generic delegate.
first_argument_type	The type of the functor first argument.
result_type	The type of the functor result.
second_argument_type	The type of the functor second argument.

Member	Description
equal_to	Constructs the functor.

Operator	Description
operator()	Computes the desired function.
operator delegate_type^()	Casts the functor to a delegate.

Remarks

The template class describes a two-argument functor. It defines the member operator operator() so that, when the object is called as a function, it returns true only if the first argument is equal to the second.

You can also pass the object as a function argument whose type is delegate_type^ and it will be converted appropriately.

Example

// cliext_equal_to.cpp   
// compile with: /clr   
#include <cliext/algorithm>   
#include <cliext/functional>   
#include <cliext/vector>   
  
typedef cliext::vector<int> Myvector;   
int main()   
    {   
    Myvector c1;   
    c1.push_back(4);   
    c1.push_back(3);   
    Myvector c2;   
    c2.push_back(4);   
    c2.push_back(4);   
    Myvector c3(2, 0);   
  
// display initial contents " 4 3" and " 4 4"   
    for each (int elem in c1)   
        System::Console::Write(" {0}", elem);   
    System::Console::WriteLine();   
  
    for each (int elem in c2)   
        System::Console::Write(" {0}", elem);   
    System::Console::WriteLine();   
  
// transform and display   
    cliext::transform(c1.begin(), c1.begin() + 2,   
        c2.begin(), c3.begin(), cliext::equal_to<int>());   
    for each (int elem in c3)   
        System::Console::Write(" {0}", elem);   
    System::Console::WriteLine();   
    return (0);   
    }

4 3  
4 4  
1 0

Requirements

Header: <cliext/functional>

Namespace: cliext

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