In the same scope, it’s not possible to have different values for default arguments. For example, this would be an error:

 void foo(int i = 0){    cout << i;}void foo(int = 1);//error

But default arguments can indeed take different values in different scopes. For example:

 int Func(void){    foo(int = 1);//ok, 1 will be used as the default value in the scope ofthis function}

To enforce this, a parameter must be supplied to the function. Declare the function without a default parameter:

 int Func(void){    foo(int);//disable the default parameter.    foo(1);//ok.    foo();//error, function foo() takes one parameter.}

The opposite is also true--a function can be declared to take adefault parameter even if it’s not defined that way.

 void foo(int i){	cout << i;}int Func(){	void foo(int = 1);//enable default parameter	foo();//ok.}