1# Copyright 2017 Rene Rivera 2# Distributed under the Boost Software License, Version 1.0. 3# (See accompanying file LICENSE_1_0.txt or copy at 4# http://www.boost.org/LICENSE_1_0.txt) 5 6import feature ; 7 8#| tag::doc[] 9 10[[bbv2.builtin.features.define]]`define`:: 11Specifies a preprocessor symbol that should be defined on the command line. 12You may either specify just the symbol, which will be defined without any 13value, or both the symbol and the value, separated by equal sign. 14 15|# # end::doc[] 16 17feature.feature define 18 : 19 : free ; 20 21#| tag::undef-doc[] 22 23[[bbv2.builtin.features.undef]]`undef`:: 24Specifies a preprocessor symbol to undefine. 25 26|# # end::undef-doc[] 27 28feature.feature undef 29 : 30 : free ; 31