Class function use of empty paranthesis

#1

what is the meaniung of bool operator()(parameters)
the first set of empty braces?

#2

hello @be10046.19
it is operator overloading .
standard syntax for overload operator
return type operator symbol of operator ( parameters){
logic
}
here we are overloading () thats why putting () symbol after operator keyword.

#3

so where in the code are we using this overloaded operator

#4

priority queue will use this overloaded operator to order elements.