void

I have the following method, and I want to know if there is anything that can go in place default(void) below because there is a compiler error that says that void is not valid here: private void applyDefaultsIfNecessary(ApplicationConfiguration configuration) { var defaults = new Dictionary<Predicate<ApplicationConfiguration>, Action<ApplicationConfiguration>>() { // { rule, action } - if rule is true, execute action { (c) => c.ConnectionString == null , (c) => c.ConnectionString = "foo" }, { (c) => c.OutputExcelFilePath == null, (c) => c.ConnectionString = "bar" }, { (c) => c.OutputDirectory

Consider the following code: template<typename F> struct S; template<typename Ret, typename... Args> struct S<Ret(Args...)> { }; template<typename... Args> using Alias = S<void(Args...)>; int main() { S<void(int)> s; Alias<int> alias; } It works fine, as expected and both the line involving S and the one involving Alias define under the hood the same type S<void(int)> . Now, consider the following changes: int main() { S<void(void)> s; // this line compiles Alias<void> alias; // this line does not } I expected it to compile, for reasons that are similar to the ones above mentioned. It goes

I haven't found anything with the specific needs of my function to do this, yes, it is for homework. So I have: public void reverseArray(int[] x) { } Precondition: x.length > 0 The fact that I can't have the function return anything, and the only argument is an array is leaving me stumped. I've tried using loops along with the recursion, but everything I've tried seems to end up with infinite instances of the function being made. I've gotten an idea/suggestion to use another function along with this one, but, how to use the original recursively is beyond me at the moment. Any help is

Functions written in PL/pgSQL or SQL can be defined as RETURNS void . I recently stumbled upon an odd difference in the result. Consider the following demo: CREATE OR REPLACE FUNCTION f_sql() RETURNS void AS 'SELECT NULL::void' -- "do nothing", no special meaning LANGUAGE sql; CREATE OR REPLACE FUNCTION f_plpgsql() RETURNS void AS $$ BEGIN NULL; -- "do nothing", no special meaning END; $$ LANGUAGE plpgsql; The function f_sql() uses the only possible way for a SELECT (as last command) in a SQL function that RETURNS void . I use it just because it is the simplest way for the purposes of this

Can this method return true somehow? public static <T> boolean isVoid(T t) { return t instanceof Void; } Sanjay T. Sharma Yes, but I'm sure that isn't really useful: public static void main(final String[] args) throws Exception { final Constructor c = Void.class.getDeclaredConstructors()[0]; c.setAccessible(true); System.out.println(c.newInstance(null) instanceof Void); } A Void class can't be instantiated so normally your code wouldn't require to deal with Void instances. The above code snippet is just an example of what havoc you can unleash when using reflection... ;-) I fail to see why you

void run() { ... if (done) return cancel(); ... } where cancel() return void . This won't compile... and I can almost understand why. But if I want to return a void from a void, why not? Instead, I end up writing something like this: if (done) { cancel(); return; } I'm not looking for code style suggestions, I want to know why Java expressly prohibits this type of void return. Any info is appreciated, thanks. A return statement with an expression returns the value of that expression. The type of cancel() is a void expression - it doesn't have a value. Logically you want to execute cancel() ,