What is an intrinsic value type?
What is an intrinsic value type, and what is the difference to non-intrinsic value types?
I couldn't find documentation about the effect of the option "Function return开发者_运维百科ing intrinsic value type without return value." in Visual Studio's VB.Net project properties' Compile page.
You're right, there doesn't seem to be any documentation here.
Consider this code:
Module Module1
Sub Main()
Console.WriteLine("Foo() is {0}", Foo())
Console.ReadKey()
End Sub
Function Foo() As Integer
End Function
End Module
With the default project properties, which have "Function returning intrinsic value type without return value" set to Warning, this compiles with this warning:
warning BC42353: Function 'Foo' doesn't return a value on all code paths. Are you missing a 'Return' statement?
and outputs
Foo is 0
By setting That project property to Error, we can make this warning halt compilation with an error.
The 'intrinsic' part comes into play if we change the code to this:
Module Module1
Sub Main()
Console.WriteLine("Foo() is {0}", Foo())
Console.ReadKey()
End Sub
Function Foo() As Bar
End Function
End Module
Structure Bar
Public a As Integer
End Structure
Now, even though Bar
is a value type, the code compiles with no warning whatever that project property is set to. We can therefore conclude that Integer
is an 'intrinsic' value type, but our Bar
is not.
What none of this tells us is what counts as an 'intrinsic' value type. Googling around, I found this page which tells me that if I fire up the Object Browser, right click in the left-hand pane and tell it to Group By Object Type, I see this:
which I think is the best we're going to get.
"intrinsic" can be taken as "built-in" in this case.
And it seems not all that relevant, you are simply missing a return.
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