Is this passing arguments by reference

[pkirk25]

// get the item, profession and its mats
int get_bill_of_materials(map<string, string> &mats_map);


map<string, string> crafted_items;
int z = get_bill_of_materials(crafted_items);

Have I passed by reference or so I need to do this?

map<string, string> crafted_items;
map<string, string> &crafted_reference = crafted_items;
int z = get_bill_of_materials(crafted_reference);

Many thanks.

 

[Alf P. Steinbach]

* pkirk25:

// get the item, profession and its mats
int get_bill_of_materials(map<string, string> &mats_map);

Presumably the following is meant to illustrate usage:

map<string, string> crafted_items;
int z = get_bill_of_materials(crafted_items);
OK.


Have I passed by reference
Yes.


or so I need to do this?

map<string, string> crafted_items;
map<string, string> &crafted_reference = crafted_items;
int z = get_bill_of_materials(crafted_reference);

No.

 

[Victor Bazarov]

// get the item, profession and its mats
int get_bill_of_materials(map<string, string> &mats_map);


map<string, string> crafted_items;
int z = get_bill_of_materials(crafted_items);

Have I passed by reference

You have.

or so I need to do this?

map<string, string> crafted_items;
map<string, string> &crafted_reference = crafted_items;
int z = get_bill_of_materials(crafted_reference);

Those two pieces are equivalent, except the second one litters
the scope with an unnecessary variable (unless you intend to
use it later somehow).

V

 

[pkirk25]

That saves a little typing then - many thanks!