Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Return true if a complete JSON has been parsed.

bool
done() const noexcept;

This function returns true when all of these conditions are met:

A complete serialized JSON has been presented to the parser, and
No error or exception has occurred since the parser was constructed, or since the last call to reset,

Constant.

No-throw guarantee.