...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 this is a signed
integer.
bool is_int64() const;
This function is used to determine if the underlying representation is a certain kind.
return this->kind() == kind::int64;
Constant.
No-throw guarantee.