How do I use boost's feature detection and other useful macros? Example: BOOST_OVERRIDE

I am working on code that needs to compile under older C++ versions (I don't know all the versions applicable). Specifically, I would like to use the macro BOOST_OVERRIDE. There are several others.

How do I reliably access these macros? I can boost/config/detail/suffix.hpp but that doesn't seem to be the right approach (delving into boost internals).

We use boost 1.78

Solution

All feature detection macros defined by Boost.Config become available by including boost/config.hpp. You should not need to include any other headers for feature detection, and certainly, you should never include anything from the detail subdirectory.

#include <boost/config.hpp>

struct interface
{
    virtual void foo() = 0;
};

struct impl :
    public interface
{
    void foo() BOOST_OVERRIDE
    {
    }
};

Boost.Config also defines a few other utilities that are defined in separate headers. For example, boost/config/auto_link.hpp allows enabling automatic linting to libraries on compilers that support this feature, and boost/config/workaround.hpp defines a few macros for testing compiler versions to apply workarounds. But for the purpose of feature detection, boost/config.hpp should be the only include you need.