# Tuple<T1,T2>.IStructuralEquatable.Equals メソッド

## 定義

`` virtual bool System.Collections.IStructuralEquatable.Equals(System::Object ^ other, System::Collections::IEqualityComparer ^ comparer) = System::Collections::IStructuralEquatable::Equals;``
``bool IStructuralEquatable.Equals (object other, System.Collections.IEqualityComparer comparer);``
``````abstract member System.Collections.IStructuralEquatable.Equals : obj * System.Collections.IEqualityComparer -> bool
override this.System.Collections.IStructuralEquatable.Equals : obj * System.Collections.IEqualityComparer -> bool``````
``Function Equals (other As Object, comparer As IEqualityComparer) As Boolean Implements IStructuralEquatable.Equals``

#### パラメーター

other
Object

このインスタンスと比較するオブジェクト。

comparer
IEqualityComparer

2 つのオブジェクトが等しいかどうかの評価に使用するメソッドを定義するオブジェクト。

Boolean

## 例

``````using System;
using System.Collections;

public class Item2Comparer<T1, T2> : IEqualityComparer
{
new public bool Equals(object x, object y)
{
// Return true for all values of Item1.
if (x is T1)
//if (typeof(x) is string)
return true;
else
return x.Equals(y);
}

public int GetHashCode(object obj)
{
if (obj is T1)
return ((T1) obj).GetHashCode();
else
return ((T2) obj).GetHashCode();
}
}

public class Example
{
public static void Main()
{
Tuple<string, double>[] distancesWalked = {
Tuple.Create("Jan", Double.NaN),
Tuple.Create("Joe", Double.NaN),
Tuple.Create("Selena", 2.01),
Tuple.Create("Jake", 1.36) };
for (int ctr = 0; ctr < distancesWalked.Length; ctr++)
{
Tuple<string, double> distanceWalked = distancesWalked[ctr];
for (int ctr2 = ctr + 1; ctr2 < distancesWalked.Length; ctr2++)
{
Console.WriteLine("{0} = {1}: {2}", distanceWalked,
distancesWalked[ctr2],
((IStructuralEquatable)distanceWalked).Equals(distancesWalked[ctr2],
new Item2Comparer<string, double>()));
}
Console.WriteLine();
}
}
}
// The example displays the following output:
//       (Jan, NaN) = (Joe, NaN): True
//       (Jan, NaN) = (Adam, 1.36): False
//       (Jan, NaN) = (Selena, 2.01): False
//       (Jan, NaN) = (Jake, 1.36): False
//
//       (Joe, NaN) = (Adam, 1.36): False
//       (Joe, NaN) = (Selena, 2.01): False
//       (Joe, NaN) = (Jake, 1.36): False
//
//       (Adam, 1.36) = (Selena, 2.01): False
//       (Adam, 1.36) = (Jake, 1.36): True
//
//       (Selena, 2.01) = (Jake, 1.36): False
``````
``````open System
open System.Collections

type Item2Comparer<'T1, 'T2 when 'T1: equality and 'T2: equality>() =
interface IEqualityComparer with
member _.GetHashCode(obj) =
match obj with
| :? 'T1 as obj->
obj.GetHashCode()
| _ ->
(obj :?> 'T2).GetHashCode()

member _.Equals(x, y) =
// Return true for all values of Item1.
match x with
| :? 'T1 ->
true
| _ ->
x.Equals y

let distancesWalked =
[| Tuple.Create("Jan", Double.NaN)
Tuple.Create("Joe", Double.NaN)
Tuple.Create("Selena", 2.01)
Tuple.Create("Jake", 1.36) |]

for ctr = 0 to distancesWalked.Length - 1 do
let distanceWalked = distancesWalked[ctr]
for ctr2 = ctr + 1 to distancesWalked.Length - 1 do
printfn \$"{distanceWalked} = {distancesWalked[ctr2]}: {(distanceWalked :> IStructuralEquatable).Equals(distancesWalked[ctr2], Item2Comparer<string, double>())}"
printfn ""
// The example displays the following output:
//       (Jan, NaN) = (Joe, NaN): True
//       (Jan, NaN) = (Adam, 1.36): False
//       (Jan, NaN) = (Selena, 2.01): False
//       (Jan, NaN) = (Jake, 1.36): False
//
//       (Joe, NaN) = (Adam, 1.36): False
//       (Joe, NaN) = (Selena, 2.01): False
//       (Joe, NaN) = (Jake, 1.36): False
//
//       (Adam, 1.36) = (Selena, 2.01): False
//       (Adam, 1.36) = (Jake, 1.36): True
//
//       (Selena, 2.01) = (Jake, 1.36): False
``````
``````Imports System.Collections

Public Class Item2Comparer(Of T1, T2) : Implements IEqualityComparer

Public Overloads Function Equals(x As Object, y As Object) As Boolean _
Implements IEqualityComparer.Equals
' Return true for all values of Item1.
If TypeOf x Is T1 Then
Return True
Else
Return x.Equals(y)
End If
End Function

Public Overloads Function GetHashCode(obj As Object) As Integer _
Implements IEqualityComparer.GetHashCode
If TypeOf obj Is T1 Then
Return CType(obj, T1).GetHashCode()
Else
Return CType(obj, T2).GetHashCode()
End If
End Function
End Class

Module Example
Public Sub Main()
Dim distancesWalked() = {
Tuple.Create("Jan", Double.NaN),
Tuple.Create("Joe", Double.NaN),
Tuple.Create("Selena", 2.01),
Tuple.Create("Jake", 1.36) }
For ctr As Integer = 0 To distancesWalked.Length - 1
Dim distanceWalked As Tuple(Of String, Double) = distancesWalked(ctr)
For ctr2 As Integer = ctr + 1 To distancesWalked.Length - 1
Console.WriteLine("{0} = {1}: {2}", distanceWalked,
distancesWalked(ctr2),
DirectCast(distanceWalked, IStructuralEquatable).Equals(distancesWalked(ctr2),
new Item2Comparer(Of String, Double)))
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
'       (Jan, NaN) = (Joe, NaN): True
'       (Jan, NaN) = (Adam, 1.36): False
'       (Jan, NaN) = (Selena, 2.01): False
'       (Jan, NaN) = (Jake, 1.36): False
'
'       (Joe, NaN) = (Adam, 1.36): False
'       (Joe, NaN) = (Selena, 2.01): False
'       (Joe, NaN) = (Jake, 1.36): False
'
'       (Adam, 1.36) = (Selena, 2.01): False
'       (Adam, 1.36) = (Jake, 1.36): True
'
'       (Selena, 2.01) = (Jake, 1.36): False
``````

## 注釈

このメンバーは、明示的なインターフェイス メンバーの実装です。 これは、Tuple<T1,T2> のインスタンスが IStructuralEquatable インターフェイスにキャストされる場合のみ、使用できます。