c# - How to Cast A Variable Using Generic Type Parameter and 'as' Operator -


i have following generic static class being used in fluent api. takes input parameter , returns wrapper class containing parameter cast generic type.:

public static foo<tout> inputas<tout>(object parameter) {      var castparameter = parameter tout;      if(castparameter == null) {          throw new exception("invalid cast");     }      return new foo<tout>(castparameter);  }

the problem castparameter == null check returns null. correct way cast object using tout generic parameter new type?

well, if parameter tout returns null, runtime type of parameter isn't tout.

don't forget operator resolution done @ compile-time, if have cast operators defined, not invoked here. if need that, can use dynamic:

public static foo<tout> inputas<tout>(dynamic parameter)  {         return new foo<tout>((tout)parameter); }

this allow runtime operator resolution, , call cast operator if 1 available. example, allow pass long, while expecting int.

however, want find different way of you're trying do; dynamic can useful, can make debugging quite bit harder, , lose compile-time warnings , errors can identify problems before happen.


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