Question

I’m programming C++ using the underscore naming style (as opposed to camel case) which is also used by the STL and boost. However, since both types and variables/functions are named all lower case, a member variable declaration as follows will lead to compiler errors (or at least trouble):

position position;

A member variable named position which is of type position. I don’t know how else to name it: It’s generally a position, but it is also the position of the object. In camel case, this would be fine with the compiler:

Position position;

But in C++ it causes problems. I don’t want to switch to camel case, use Hungarian notation or add a trailing underscore because of that, so I’m wondering: Is it a good practice to name a member like a type anyways?

In C, it is pretty common to use cryptic one-letter variables for this:

int i;

But I find that a bit, well, cryptic:

position p;

Are there any rules of thumb for variable naming I can use to avoid this?

There are more examples in my code if you need something to work on:

mouse_over(entity entity) // Returns true if the mouse is over the entity

manager &manager; // A reference to the framework's manager

audio audio; // The audio subsystem

Edit:

I was curious to see if Bjarne Stroustrup himself has something to say on this issue. Apparently, he hasn’t, but he suggests coding conventions that would work around my compiler problems:

For example, capitalize nonstandard library user-defined types and start nontypes with a lowercase letter

That’d be consistent with STL and boost, so I might use that. However, most of you agree that this naming should be avoided whether it compiles or not. So does Stroustrup:

it is unwise to choose names that differ only by capitalization.

Answer 1

The local meaning is rarely a good unique global description of the type:

cartesian_point_2d position;  // rectangular, not polar coordinates
mouse_over(ui_entity entity); // not a business layer entity
xyz_manager& manager;         // what's a manager without something to manage?
audio_system audio;