switch, constant expression

[heliusa]

I have declarated this:
const int peasant = 300;
const int footman = 900;
const int archer = 500;
const int griffon = 1500;
const int hero = 10000;
const int space = 0;
int Field[10][12];

And now my array Field[][] is filled with the declarated consts and I have a function to print is but in more appropriate view:
void Battlefield::PrintField()
{
string piece;
for (int i = 0; i < 10; i++)
{
cout << endl;
for (int j = 0; j < 12; j++)
{
switch (Field[i][j])
{
case 0: piece = " - "; break;
case space: piece = " "; break;
case peasant: piece = " P "; break;
case -peasant: piece = " EP "; break;
case archer: piece = " A "; break;
case -archer: piece = " EA "; break;
case griffon: piece = " G "; break;
case -griffon: piece = " EG "; break;
case footman: piece = " F "; break;
case -footman: piece = " EF "; break;
case hero: piece = " H "; break;
case -hero: piece = " EH "; break;
}
It gives me back that space, peasant, etc cannot be used in a constant expression

[Duthomhas]

constexpr int peasant = 300;

[PanGalactic]

Should work as written. Show the exact error message and line number that it refers to. And what compiler are you using?

[heliusa]

I tried in VS and the error indicates all case lines:
197 IntelliSense: 'this' cannot be used in a constant expression Battlefield.cpp 51 10

Also tried in CodeBlocks where I have the same thing:

|293|error: 'Battlefield::space' cannot appear in a constant-expression|

I tried with constexpr instead of const, but then the errors are:

|242|error: 'constexpr' does not name a type|

|296|error: 'archer' was not declared in this scope|

In VS it even cannot recognize "constexpr"...

[heliusa]

Also I have this warning about the same lines:

|257|warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]|

[PanGalactic]

"'this' cannot be used in a constant expression" is very true. Is it possible you have member variables or functions that alias your global constants?

[jlb]

It would probably help if you showed the complete class definition and implementation.

Part of your problems seem to be that you are using C++11 constructs but are not using a C++11 compiler.


Oh and never rely on Intellisense errors, always compile your code and refer to the actual compile errors. Intellisense has is known to be wrong in many occasions.