Specifies whether a function could throw exceptions.| en.cppreference.com
Each C++ expression (an operator with its operands, a literal, a variable name, etc.) is characterized by two independent properties: a type and a value category. Each expression has some non-reference type, and each expression belongs to exactly one of the three primary value categories: prvalue, xvalue, and lvalue.| en.cppreference.com
Declares a named variable as a reference, that is, an alias to an already-existing object or function.| en.cppreference.com
Constructs a closure (an unnamed function object capable of capturing variables in scope).| en.cppreference.com
When certain criteria are met, the creation of a class object from a source object of the same type (ignoring cv-qualification) can be omitted, even if the selected constructor and/or the destructor for the object have side effects. This elision of object creation is called copy elision .| en.cppreference.com