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
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
Returns whether the object holds a valid result.
bool has_value() const;
Having this->has_value()
is a precondition to call all data accessors. Objects populated by connection::query,
connection::execute_statement or their async
counterparts are guaranteed to have this->has_value() == true.
No-throw guarantee.