estd::variant

Overview

estd::variant represents a type-safe union similar to std::variant. It holds a value of exactly one of its alternative types.

The size of the variant equals that of its largest alternative plus one size_t to store the index of the alternative.

Preconditions	Make sure to include the appropriate library header for variant.
Assumptions of usage	`estd::variant` can be used hold a value of exactly one of its alternative types.
Recommended usage guidance	`estd::variant` can be used in situation where a program need a type-safe union of fixed types, allowing to work with heterogeneous data in more structured manner.