Initialize a static const member with a template argument

I have a few lines that compile well on my system but don't compile on a colleagues system. That's why I would like to ask what the go-to solution for the problem would look like. I have to deal with a enum that implicitly defines how much space I have to provide for an std::array. Other parts of the code also make use of FooSize being static. (Optimization)

My current implementation looks like this

enum class FooType
{
    ShortFoo,
    LongFoo
};

// defined in a different file
template <FooType FType>
class FooContainer
{
public:

    static const unsigned int FooSize {(FType == FooType::ShortFoo) ? 32 : 64 };

    std::array<float, FooSize> fooArray;

};

The code seems to create issues on older llvm / clang compilers. 32 and 64 are actually provided via pre processor defines. I could just skip the FooType and use the size as an template argument but I would like to know what the most reliable method of initializing FooSize would be.