In the given query, the error message “no instance(s) of type variable(s) t exist so that void conforms to t” indicates that there is a problem with the type inference or type compatibility in the code.
When the compiler encounters this error, it means that it cannot find a suitable type that satisfies the requirements of the code. Specifically, it cannot find any instance of type variable(s) ‘t’ that would be compatible with a void type.
To understand this error better, let’s consider an example. Assume that you have a generic method called ‘print’ that is supposed to accept any type ‘T’ and print it. The code for this method would look like:
public static <T> void print(T value) {
System.out.println(value);
}
Now, if you try to call this method with a void type argument, like:
print(voidValue);
The compiler will throw the error mentioned in the query. This is because ‘void’ is not a valid type that can be used as an argument for a generic method with a ‘void’ return type.
To fix this error, you need to make sure that the type argument passed to the generic method is a valid non-void type. For example, you can call the ‘print’ method with an Integer argument:
Integer intValue = 10;
print(intValue);
In this case, the compiler will infer the type ‘Integer’ for the type variable ‘T’ in the ‘print’ method and the code will execute without any errors.