对于盒装值,"is"运算符在立即窗口中的工作方式不同

Question

对于盒装int,例如object boxedInt = 0在代码中定义,is object并在Visual Studio的立即窗口中is int返回false.这是一个bug,不是吗？

码:

int normalInt = 0;

Debug.WriteLine(normalInt.GetType().FullName); // System.Int32
Debug.WriteLine(normalInt is object);          // true
Debug.WriteLine(normalInt is int);             // true
Debug.WriteLine(normalInt is System.Int32);    // true

object boxedInt = 0;

Debug.WriteLine(boxedInt.GetType().FullName); // System.Int32
Debug.WriteLine(boxedInt is object);          // true
Debug.WriteLine(boxedInt is int);             // true
Debug.WriteLine(boxedInt is System.Int32);    // true

即时窗口:

normalInt.GetType().FullName
"System.Int32"
normalInt is object
true
normalInt is int
true
normalInt is System.Int32
true

boxedInt.GetType().FullName
"System.Int32"
boxedInt is object
false                                         // WTF?
boxedInt is int
false                                         // WTF?
boxedInt is System.Int32
false                                         // WTF?

object boxedInt2 = 0;
Expression has been evaluated and has no value
boxedInt2.GetType().FullName
"System.Int32"
boxedInt2 is object
true
boxedInt2 is int
true
boxedInt2 is System.Int32
true

Microsoft Visual Studio Enterprise 2017
版本15.3.3
VisualStudio.15.Release/15.3.3 + 26730.12

Microsoft .NET Framework
版本4.7.02046

Visual C#2017 00369-60000-00001-AA135

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带Watch窗口的截图:

Answer 1

在“工具”->“选项”->“调试”下，请启用“使用旧版 C# 和 VB 表达式求值器”选项，然后再次调试。

更新：

该问题已报告如下：

https://developercommunity.visualstudio.com/content/problem/31283/and-operation-of-boolean-is-wrong.html