Remove reinterpret_cast

[Halalaluyafail3]

It is not valid to use reinterpret_cast in a constant expression, and even outside of constant expressions the use is UB as described in #54. Instead of using a byte array, a union which contains an array can be used for the same purpose. This makes the name of the class wrong, but I have left it unchanged for now.

[wusatosi]

Hi @Halalaluyafail3 , this implement is based on the original inplace vector paper (P0843) without implementing trivial unions (P3074) (as currently there's no compiler support).

In P0843, inplace vector is only required to be constexpr for trivial element type T.

This is designed that for non trivial types, the default constructor is not called unnecessarily and allows default constructor deleted element type.

You can read more about this here: The storage problem.

[Halalaluyafail3]

Ok, if that is intended it seems misleading to use constexpr in the definitions of storage_data.

[wusatosi]

Ok, if that is intended it seems misleading to use constexpr in the definitions of storage_data.

good point, it shouldn't be.

[JeffGarland]

So it seems like we aren't going to merge this, but maybe the cast should have a big juicy comment on it that explains why it's there for now?

[wusatosi]

See #102 .