stdvariantshort

stdvariantshort is a hypothetical C++ concept that could represent a specialized, potentially more efficient, implementation of `std::variant` when the number of possible types is small. `std::variant` is a C++ standard library type that can hold a value of one of a specified set of types. In scenarios where the number of alternative types is limited, such as two or three, a specialized implementation might offer performance benefits.

Such a `std::variantshort` could achieve efficiency through various means. One approach might involve using a more compact internal representation compared to the general `std::variant`, which typically needs to accommodate the largest type plus a tag to indicate the currently active type. For a small, fixed number of types, this overhead could be reduced. Another possibility is that `std::variantshort` could optimize type checking and value access through compiler intrinsics or specialized template metaprogramming techniques that are not feasible or as effective for a variable number of types.

The primary motivation for a concept like `std::variantshort` would be to provide developers with a tool that offers the type-safety and expressiveness of `std::variant` without the potential performance penalty in common, simpler use cases. This could be particularly relevant in performance-critical code where the overhead of a general-purpose `std::variant` might be undesirable. While `std::variant` is already a powerful tool, specific use cases often benefit from tailored solutions.