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

QVM: Quaternions, Vectors, Matrices

BOOST_QVM_INLINE_CRITICAL

#include <boost/qvm/inline.hpp>

#ifndef BOOST_QVM_INLINE_CRITICAL
#define BOOST_QVM_INLINE_CRITICAL BOOST_QVM_FORCE_INLINE
#endif

Boost QVM uses BOOST_QVM_INLINE_CRITICAL in definitions of functions that are critical for the overall performance of the library, such as functions that access individual vector and matrix elements.