import modules ;

rule target-source ( targets * : sources * : properties * )
{
    if [ modules.peek : NT ]
    {
        main on $(<) = "int main() {}" ;
    }
    else
    {
        main on $(<) = "\"int main() {}\"" ;
    }
}

actions target-source
{
    echo "NM target source consuming " $(>)
    echo $(main) > $(<)      
}

rule cpp-mark ( targets * : sources * : properties * )
{
}

actions cpp-mark
{
    echo "CPP-MARK consuming " $(>)
    touch $(<)
}