Const functionality

#1

Why following declaration gives error:
bool operator () (student& x, const student& y) ?

#2

Your question is not clear enough. Please copy and paste the whole question or code so that i can check.

#3

Study the following code carefully.

struct student{
string name;
float cgpa;
student(string name, float cgpa){
this -> name = name;
this -> cgpa = cgpa;
}
};

struct comp{
bool operator () (const student& x, student y) {
return x.name < y.name;
}
};

set < student, comp > batch;
The above code compiles successfully. Choose which of the following declarations of the function operator () will give a compilation error.

bool operator () (student x, student y)

bool operator () (const student& x, const student& y)

bool operator () (student& x, const student& y)

None of these

#4

When you are sending by reference (by using & operator) to a custom comparator it must be sent with const type. const means that it will become immutable.
bool operator () (student& x, const student& y) will give error as the first parameter is not with a const.

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#5

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