better-enums/doc/tutorial/3-iterate.md
Anton Bachin e1e237a4ea Renamed top-level macro ENUM to BETTER_ENUM.
To reduce name clashes.

Fixes #11.
2015-10-04 11:03:08 -05:00

1.3 KiB

Iteration

Better Enums makes it easy to iterate over the values you have declared. For example, this:

#include <iostream>
#include <enum.h>

<em>BETTER_ENUM(Channel, int, Red, Green = 2, Blue)</em>

int main()
{

    <em>for</em> (<em>size_t index = 0</em>; <em>index < Channel::_size()</em>; <em>++index</em>) {
        Channel     channel = <em>Channel::_values()[index]</em>;
        std::cout << channel._to_integral() << " ";
    }
    std::cout << std::endl;

will print "0 2 3". And this:

    <em>for</em> (<em>size_t index = 0</em>; <em>index < Channel::_size()</em>; <em>++index</em>) {
        const char  *name = <em>Channel::_names()[index]</em>;
        std::cout << name << " ";
    }
    std::cout << std::endl;

will print "Red Green Blue".


If you are using $cxx11, you can have much nicer syntax:

    <em>for (Channel channel : Channel::_values())</em>
        std::cout << <em>channel._to_integral()</em> << " ";
    std::cout << std::endl;

    <em>for (const char *name : Channel::_names())</em>
        std::cout << <em>name</em> << " ";
    std::cout << std::endl;

    return 0;
}

%% description = Using Better Enums to iterate over all the constants of an enum, as well as over its names. Also shows the same with C++11 for-each syntax.