c# - Generics explicit conversion -

i implemented explicit conversion string object called foo.

so => foo f = (foo)"foo data"; works

i need implement function cast string generic t, t in case foo datatype.

public t get<t>(object o){       // return false       if (typeof(t).isassignablefrom(typeof(string)))       {             // when pass if above throws invalid cast exception             return (t)(object)str;       }       return null;  }  // when call this, generated error // invalid cast 'system.string' foo foo myobj = get<foo>("another foo object");   // when use dynamic keyword works c# 4.0+ feature, function in older framework return (t)(dynamic)str; 

an example uses reflection:

class program {     static void main(string[] args)     {                    foo myobj = typeresolver.get<foo>("foo data");                 } }  class typeresolver {     public static t get<t>(object obj)     {         if (typeof(t).canexplicitlycastfrom<string>())         {                                          return obj.castto<t>();         }         return default(t);     } }  public static class extensions {     public static bool canexplicitlycastfrom<t>(this type type)     {         if (type == null)             throw new argumentnullexception("type");          var paramtype = typeof(t);         var castoperator = type.getmethod("op_explicit",                                          new[] { paramtype });         if (castoperator == null)             return false;          var parametres = castoperator.getparameters();         var paramtype = parametres[0];         if (paramtype.parametertype == typeof(t))             return true;         else             return false;     }      public static t castto<t>(this object obj)     {                     var castoperator = typeof(t).getmethod("op_explicit",                                          new[] { typeof(string) });         if (castoperator == null)             throw new invalidcastexception("can't cast " + typeof(t).name);         return (t)castoperator.invoke(null, new[] { obj });     } }