Boost C++ 库

...世界上备受推崇且设计精湛的 C++ 库项目之一。 — Herb Sutter 和 Andrei Alexandrescu, C++ Coding Standards

Global a4 - Boost C++ 函数库

Global a4

boost::xpressive::a4

// In header: <boost/xpressive/regex_primitives.hpp>

unspecified a4;