{"id":1658,"date":"2017-10-27T01:00:42","date_gmt":"2017-10-27T01:00:42","guid":{"rendered":"https:\/\/www.fluentcpp.com\/?p=1658"},"modified":"2017-10-29T00:41:22","modified_gmt":"2017-10-29T00:41:22","slug":"function-aliases-cpp","status":"publish","type":"post","link":"https:\/\/www.fluentcpp.com\/2017\/10\/27\/function-aliases-cpp\/","title":{"rendered":"Function Aliases In C++"},"content":{"rendered":"

\"Daily<\/a><\/p>\n

One thing that dramatically improves the expressiveness of a piece of code is respecting its levels of abstractions<\/a>.<\/p>\n

It sometimes involves massive refactorings, but in many cases it just comes down to choosing good names in your code<\/a>. Picking a name that is consistent with the abstraction level of the surrounding code can make a difference between making a reader scratch their head and making them… read on.<\/p>\n

For this reason, today I’d like to share with you a feature made usable by C++11, that I think didn’t get as much credit as it deserves:\u00a0function aliases<\/strong>.<\/p>\n

C++03: one-liners<\/span><\/h3>\n

Can you see a case where it’s useful to define a function that has just one line of code<\/strong>? And what if that line is just forwarding the parameters to another function?<\/p>\n

int f(int parameter)\r\n{\r\n    return g(parameter);\r\n}<\/pre>\n
This seems pointless: why not call g<\/code> directly, instead of calling f<\/code>?<\/p>\n
In fact this can be useful, in the case where the name of g<\/code> isn’t meaningful in the call site. Introducing f<\/code>\u00a0gives your call site a way to read”\u00a0f<\/code>” instead of “g<\/code>“.<\/p>\n
Also, it decouples the call site from g<\/code>, which becomes useful if we want to replace g<\/code>\u00a0with something else and there are multiple places in the code where it was called. When you use f<\/code> you only need to change it at one place: inside\u00a0f<\/code>.<\/p>\n
Here is an example, adapted from the excellent book Code Complete<\/a> from Steve McConnell. Let’s take a function that generates a new Id. It happens that right now, this Id is generated by the database. But this could change in the future. So if we have a function newIdFromDatabase()<\/code>\u00a0it would be worth considering wrapping it into another function, that only mention that we’re getting a new Id:<\/p>\n
int newId()\r\n{\r\n    return newIdFromDatabase();\r\n}<\/pre>\n
This way:<\/p>\n