What is the correct way to convert a string to an unknown numeric type?

I am creating a type converter for use in a native library that should be able to convert from any type returned by the database (long, DBNull, bool, string, etc.). ) to any compatible type.

This all works fin and dandy for items that might be deprived:

try { return (T)value } catch(InvalidCaseException) { }

      

        
        
        
      

    

Or can be parsed:

see Convert to Nullable <T> from String using Reflection

However, I push the brick wall when I want this desired behavior:

Assert.That(
    2,
Is.EqualTo(
    Converter<long>.Convert("2.1")
));

      

        
        
        
      

    

The problem is that the Pasre and TryParse functions throw this back as an invalid format when the actual desired result is decimal truncation.

Do you think the best way to parse a string like "2.1" to an unknown value type is using reflection?

EDIT: I am currently using:

if (Nullable.GetUnderlyingType(t) != null)
{
    t = Nullable.GetUnderlyingType(t);
}

MethodInfo parse = t.GetMethod("Parse", new Type[] { typeof(string) });

if (parse != null)
{
    object parsed = parse.Invoke(null, new object[] { value.ToString() });
    return (T)parsed;
}
else
{
    throw new InvalidOperationException("The value you specified is not a valid " + typeof(T).ToString());
}