Q:

Naming constants in C++

I am replacing my #defines, for instance #define NUM_SLIDER_POSITIONS 5 for constant variables. Should I keep the old naming like:
const unsigned int NUM_SLIDER_POSITIONS = 5;

Or should I use something more like:
const unsigned int kNumSliderPositions = 5;

.
EDIT: The post has been put on hold, but anyway I'd like to sum up your answers:
Other option would be using underscores as a separators using lower case letters:
const unsigned int num_slider_positions = 5;

Constant identifier.
Regarding the use of a prefix as a way of identifying constants , the most common options are not using it, as it may not add relevant information:
const unsigned int num_slider_positions = 5;

Use a "k" before the name:
const unsigned int k_num_slider_positions = 5;

Or declaring the variable inside a class or namespace, in order to avoid polluting the global scope and providing a more self-explanatory name:
namespace defaults // or "config", or "settings" or something like that
{
    const unsigned int num_slider_positions = 5;
}

Client code:
int slider_positions = defaults::num_slider_positions;

A:

I am replacing my #defines for constant variables.

Kudos! :)

Should I keep the old naming like: [all-caps]

If the coding conventions of your project designate constants to be in all-caps, you should (as it spares you an effort). Otherwise, you should not (because it will be confusing later, for maintenance).

Or should I use something more like: [bastardized hungarian convention]

This is up to you. Personally I do not like to add weird letters for my constants, because when reading the code - or writing it - I do not care much that they are constant (and if I try to write into them, the compiler will let me know).
My (personal) choice would be to use a namespace for providing context (instead of a prefix), along these lines:
namespace defaults // or "config", or "settings" or something like that
{
    const unsigned int num_slider_positions = 5;
}

Client code:
int slider_positions = defaults::num_slider_positions;

I find this to be a superior alternative, because the context is more self-explanatory (than a "k" in front of it, or a "g" or a whatever else).

