Class internal_capacity

include/function2/function2.hpp:1081–1091

/// control and vtable.
template <typename Capacity, typename = void>
struct internal_capacity {
  /// We extend the union through a technique similar to the tail object hack
  typedef union {
    /// Tag to access the structure in a type-safe way
    data_accessor accessor_;
    /// The internal capacity we use to allocate in-place
    struct alignas(Capacity::alignment) {
      unsigned char data[Capacity::capacity];
    } capacity_;
  } type;
};
template <typename Capacity>
struct internal_capacity<
    Capacity, std::enable_if_t<(Capacity::capacity < sizeof(void*))>> {