...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Returns the kind of this JSON value.
kind
kind() const noexcept;
This function returns the discriminating enumeration constant of type
json::kind
corresponding to the underlying representation stored in the container.
Constant.
No-throw guarantee.