Misc tasks to check later

[ptheywood]

List of notes to self related to this work, things to check later / seek clarification on at some point:

• Does __host__ __device__ constexpr char [] VARIABLE_NAME = "var"; behave the same in FLAME GPU device code as `"var" would?
  • I.e. check if this has any performance implication on runtime (i.e. generated PTX/assembly) or device memory usage. It shouldn't with it being constexpr, but it might?. a constexpr function might be an alt for namespaced non-macro compile time literal strings.
• Is it possible to make enum class X : std::uint32_t usable with F2 methods without lots of static casting back and forth?
• Should time series data row 0 be initialised state or at the end of day/timestep 0?