...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Returns true
if the serialization is complete.
bool done() const noexcept;
This function returns true
when all of the characters in the serialized representation of the value
have been read.
Constant.
No-throw guarantee.