c# - Check to see if a given object (reference or value type) is equal to its default -

i'm trying find way check , see if value of given object equal default value. i've looked around , come this:

    public static bool isnullordefault<t>(t argument)     {         if (argument valuetype || argument != null)         {             return object.equals(argument, default(t));         }         return true;     } 

the problem i'm having want call this:

            object o = 0;             bool b = utility.utility.isnullordefault(o); 

yes o object, want make figure out base type , check default value of that. base type, in case, integer , want know in case if value equal default(int), not default(object).

i'm starting think might not possible.

in example, integer boxed , therefore t going object, , default of object null, that's not valuable you. if object value type, instance of (which default) use comparison. like:

if (argument valuetype) {    object obj = activator.createinstance(argument.gettype());    return obj.equals(argument); } 

you'd want deal other possibilities before resorting this. marc gravell's answer brings points consider, full version of method, might have

public static bool isnullordefault<t>(t argument) {     // deal normal scenarios     if (argument == null) return true;     if (object.equals(argument, default(t))) return true;      // deal non-null nullables     type methodtype = typeof(t);     if (nullable.getunderlyingtype(methodtype) != null) return false;      // deal boxed value types     type argumenttype = argument.gettype();     if (argumenttype.isvaluetype && argumenttype != methodtype)      {         object obj = activator.createinstance(argument.gettype());         return obj.equals(argument);     }      return false; }