[boost] [predef] check and require logical operators and multiple expression questions

Subject: [boost] [predef] check and require logical operators and multiple expression questions
From: Edward Diener (eldiener_at_[hidden])
Date: 2016-05-01 14:15:40

Is there any difference in the result when you use the 'and' logical 
operator or simplty specify more than one expression:

lib my_special_lib : source.cpp
     : [ predef-require "BOOST_OS_WINDOWS" and "BOOST_COMP_CLANG"] ;

lib my_special_lib : source.cpp
     : [ predef-require "BOOST_OS_WINDOWS" "BOOST_COMP_CLANG"] ;

Are both the above equivalent ?

Can I use both 'and' and 'or' in an expression ? If so does 'and' bind 
before 'or' does, so that 'expression1 and expression2 or expression3' 
is conceptually '(expression1 and expression2) or expression3' ?

Can I use parentheses to bind an expression with 'and' and 'or' ?