Given a string denoting a type, I need to know if it's a value or reference type

I'm writing a T4 template and got stuck on this. If consumers of the template write:

Please generate stuff for: string myString

I need to generate

if (myString != null)
{
    DoStuffWith(myString)
}

Whereas if they write

Please generate stuff for: int myInt

I need to generate simply

DoStuffWith(myInt)

And this needs to work with custom value/reference types too.

If I forced the template consumers to write System.String myString or System.Int32开发者_如何学运维 myInt, I imagine this could be done without trouble; there's presumably some GetTypeFromFullTypeName method hiding in the framework somewhere. But I don't want to make them do that.

Any ideas on how my T4 template could get at this information, so I could conditionally generate the right code?

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1. Get the corresponding instance of the Type class (i.e. Type.GetType or Assembly.GetType).

2. Check the IsValueType property.

The number of types with "short names" is very limited, they're actually C# keywords. So you can use a case statement, e.g. case "string": return typeof (string);

You'll also need some rules for ?, and for finding a specific concrete version of generic classes (recursion will be helpful). Don't try to translate int? into System.Nullable``1[System.Int32], instead use typeof(System.Nullable<>).MakeGenericType(FindType("int")).

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You could emit the null check always, even for value types. This is not a compiler error, but produces a warning which you could suppress:

#pragma warning disable CS0472 
if (myInt != null)
{
    DoStuffWith(myInt)
}
#pragma warning restore CS0472