[Boost-build] clfags option with space in user-config.jam

Subject: [Boost-build] clfags option with space in user-config.jam
From: Edward Diener (eldiener_at_[hidden])
Date: 2015-05-01 07:58:22

How do I specify a cflags or cxxflags option, in a jamfile, that needs a 
space in the actual option ?

For instance the gcc -isystem option is:

-isystem dir

If I specify, in user-config.jam,

using gcc : : : <cflags>"-isystem some_directory" ;

Boost build thinks this is two separate options "isystem" and 
"some_directory". What is the correct syntax ?