Force C# compiler error based on const value

Question

I have a private const int defined in a C# class. I want compilation to fail with an error if the value of this int mod 3 != 0. How can I accomplish this?

Answer 1

Although there is an #error pre-processor directive for generating compile-time errors, there is no way for it to be based on the existence of a const value. It only works with compiler symbols, like "DEBUG", for which a value can't be assigned.

Answer 2

Try this:

if (MY_CONST % 3 != 0) { int compilerError = 1 / 0; }

Answer 3

Sorry, that code I said below won't work, but this will :)

int pointless = 1 / (MY_CONST % 3);

The reason why this will work is because you'll get a compile time, "can't devide by zero" error. Your "MY_CONST" field will have to be anything that (once modded by 3) will not be equal to zero.

Answer 4

Timothy Khouri almost got it. It should be this:

int compilerError = 1 / (MY_CONST % 3 == 0 ? 1 : 0);