default properties question

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-03-07 03:53:06

I've a design issue: suppose we've link-incompatible property, for example 
<rtti>, and the following project:

exe a : a.cpp l ;
lib l : l.cpp ;

Then both targets will be build with default value -- <rttin>on. No problem.
Another example:

exe a : a.cpp l : <rtti>on ;
lib l : l.cpp : <rtti>off ;

Here, first targets *explicitly* asks for <rtti>on and uses another one, which
explicitly requires something else. Since <rtti> is not link-compatible, this 
is an error. Now the question:

exe a : a.cpp l ;
lib l : l.cpp : <rtti>off ;

The first target will be build with default value <rtti>on. What about the 
second:
1. Should we request it with <rtti>on and get an error, or
2. Should we request if without any <rtti> setting and allow it to be
built with <rtti>off

I think (1) is way safer. But interested in other opinions.

- Volodya