...one of the most highly
regarded and expertly designed C++ library projects in the
world. — Herb Sutter and Andrei
// In header: <boost/yap/user_macros.hpp> BOOST_YAP_USER_UNARY_OPERATOR(op_name, expr_template, result_expr_template)
Defines operator overloads for unary operator op_name that each take an expression instantiated from expr_template and return an expression instantiated from the result_expr_template expression template. One overload is defined for each of the qualifiers
&&. For the lvalue reference overloads, the argument is captured by reference into the resulting expression. For the rvalue reference overload, the argument is moved into the resulting expression.