Is there a simple way to convert an enum class to a string (c++)?

Question

while there are solutions to easily convert an enum to a string, I would like the extra safety benefits of using enum class. Is there a simple way to convert an enum class to a string?

(The solution given doesn't work, as enum class can't index an array).

_"The solution given doesn't work, as enum class can't index an array"_ Can you elaborate about this, or give a sample? I don't understand in which way it should be different for `enum class`. — πάντα ῥεῖ, Jan 14 '15 at 09:29
@πάνταῥεῖ You cannot implicitly convert an `enum class` to its underlying type, which is kind of the point of them. — sjdowling, Jan 14 '15 at 09:31
Array-based solutions aren't usable when the vaues in the enum are user-specified, like { Good= 1, Bad= 2, Unknown= ~0 } — Yves Daoust, Jan 14 '15 at 09:39

score 2 · Accepted Answer · answered Jan 14 '15 at 09:33

You cannot implicitly convert to the underlying type but you can do it explicitly.

enum class colours : int { red, green, blue };
const char *colour_names[] = { "red", "green", "blue" };
colours mycolour = colours::red;
cout << "the colour is" << colour_names[static_cast<int>(mycolour)];

It's up to you if that is too verbose.

score 1 · Answer 2 · answered Jan 14 '15 at 09:34

1

Are you using VS C++. Below the code example of MSDN

using namespace System;
public ref class EnumSample
{
public:
   enum class Colors
   {
      Red = 1,
      Blue = 2
   };

   static void main()
   {
      Enum ^ myColors = Colors::Red;
      Console::WriteLine( "The value of this instance is '{0}'", myColors );
   }

};

int main()
{
   EnumSample::main();
}

/*
Output.
The value of this instance is 'Red'.
*/

answered Jan 14 '15 at 09:34

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What about { Red= 0x100, Blue= 0x10000, Green= 0x1000000 } ? – Yves Daoust Jan 14 '15 at 09:36
1

Brilliant SSCE, could you explain the `^` syntax to me as I'm not familiar with it? – Mike H-R Jan 14 '15 at 09:43
@πάνταῥεῖ thanks, with c++cli I found an explanation of the syntax [here](http://stackoverflow.com/questions/202463/what-does-the-caret-mean-in-c-cli) – Mike H-R Jan 14 '15 at 09:52

Is there a simple way to convert an enum class to a string (c++)?

2 Answers2