CLIネストされたジェネリック型とジェネリックメソッド

Question

実装定義の振る舞いに遭遇しましたか？ここで

はコンテキストです：

public class GenericClass<T> 
{ 
    public class NestedGenericClass<U> 
    { 
     public void GenericMethod<K>() 
     { 
     } 
    } 
} 

は、ここでの行動です。この単体テストは書かれた通りに渡ります。私の実際の質問は、「不気味な」（私にとっては今のように）行動の前にコメントとして記載されています。

[TestMethod] 
public void TestNestedGenericMethod() 
{ 
    Type openType = typeof(GenericClass<>.NestedGenericClass<>); 
    Type closedType = typeof(GenericClass<bool>.NestedGenericClass<int>); 
    /* Note there is absolutely no representation of the following as a [unique] type, via the 
    * typeof operator or the Reflection API, even though the metadata TypeSpec signature 
    * should in theory be able to reference it. This is the original reason I wrote these 
    * tests. 
    * Type partiallyOpenType = typeof(GenericClass<bool>.NestedGenericClass<>); 
    */ 

    MethodInfo openTypeOpenMethod = openType.GetMethod("GenericMethod"); 
    MethodInfo closedTypeOpenMethod = closedType.GetMethod("GenericMethod"); 
    MethodInfo closedTypeClosedMethod = closedTypeOpenMethod.MakeGenericMethod(typeof(long)); 

    Assert.IsNotNull(openTypeOpenMethod); 
    Assert.IsNotNull(closedTypeOpenMethod); 
    Assert.IsNotNull(closedTypeClosedMethod); 

    Assert.AreNotSame(openTypeOpenMethod, closedTypeOpenMethod); 
    Assert.AreNotSame(openTypeOpenMethod, closedTypeClosedMethod); 
    Assert.AreNotSame(closedTypeOpenMethod, closedTypeClosedMethod); 

    /* What on earth?! 
    * 1. Is the following covered in the CLI spec and/or is it implementation-defined? 
    * 2. Is there any potential use of this behavior (inside the runtime itself OR outside)? 
    * 3. Will I ever hit a MethodDefSig (§23.2.1)/MethodRefSig (§23.2.2)/MethodSpecSig (§23.2.15) that resolves to this? 
    */ 
    MethodInfo openTypeClosedMethod = openTypeOpenMethod.MakeGenericMethod(typeof(long)); 
    Assert.IsNotNull(openTypeClosedMethod); 
    Assert.AreNotSame(openTypeClosedMethod, openTypeOpenMethod); 
    Assert.AreNotSame(openTypeClosedMethod, closedTypeOpenMethod); 
    Assert.AreNotSame(openTypeClosedMethod, closedTypeClosedMethod); 

    Assert.AreSame(closedTypeOpenMethod, closedTypeClosedMethod.GetGenericMethodDefinition()); 
    Assert.AreSame(openTypeOpenMethod, openTypeClosedMethod.GetGenericMethodDefinition()); 
} 

Answer 1

これはとても奇妙ではありません。

//void GenericClass<>.NestedGenericClass<>.GenericMethod<Int64>() 
openTypeClosedMethod.ContainsGenericParameters = true 
openTypeClosedMethod.IsGenericMethodDefinition = false 

//void GenericClass<>.NestedGenericClass<>.GenericMethod<K>() 
openTypeOpenMethod.ContainsGenericParameters = true 
openTypeOpenMethod.IsGenericMethodDefinition = true 

//void GenericClass<bool>.NestedGenericClass<int>.GenericMethod<K>() 
closedTypeOpenMethod.ContainsGenericParameters = true 
closedTypeOpenMethod.IsGenericMethodDefinition = true 

//void GenericClass<bool>.NestedGenericClass<int>.GenericMethod<Int64>() 
closedTypeClosedMethod.ContainsGenericParameters = false 
closedTypeClosedMethod.IsGenericMethodDefinition = false 

MethodInfo closedGeneratedMethod = closedTypeClosedMethod.GetGenericMethodDefinition(); 
MethodInfo openGeneratedMethod = openTypeClosedMethod.GetGenericMethodDefinition(); 

//void GenericClass<bool>.NestedGenericClass<int>.GenericMethod<K>() 
closedGeneratedMethod.ContainsGenericParameters = true 
closedGeneratedMethod.IsGenericMethodDefinition = true 

//void GenericClass<>.NestedGenericClass<>.GenericMethod<K>() 
openGeneratedMethod.ContainsGenericParameters = true 
openGeneratedMethod.IsGenericMethodDefinition = true 

ちょうどアサートからのすべての組み合わせを比較します。

P.S.あなたが逃した

Assert.AreNotSame(closedTypeOpenMethod, openTypeOpenMethod);