Question

At my workplace, usually default parameters are specified in the declaration.What is the normal custom? Should I specify default parameters in method declaration or method definition?

EDIT: Is there any way to specify default parameters for references?

EDIT: Can someone please provide an example of default arguments for reference parameters?

Answer 1

ybungalobill has already answered the question about where.

Regarding references, for a reference to const T you can just specify a default value directly.

For a reference to non-const you need to specify the default “value” as a reference to non-const. This might be a global, or an instance of a class with suitable conversion. E.g.,

#include <iostream>

struct DummyInt
{
    int dummy;
    operator int& () { return dummy; }
    DummyInt(): dummy( 0 ) {}
};

void foo( int& v = DummyInt() ) {}  // Whatever

int main()
{
    int x   = 42;
    foo( x );
    foo();
}

Cheers & hth.,

– Alf