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
Retrieves the contained diagnostics (rvalue reference accessor).
diagnostics
diag() && noexcept;
If *this
contains an error, retrieves the associated diagnostic information by
moving it. Otherwise (if this->has_statement() || this->has_results()),
returns an empty (default-constructed) error.
No-throw guarantee.