[boost] [Filesystem] Notes for Cygwin users

From: Beman Dawes (bdawes_at_[hidden])
Date: 2004-02-22 10:04:25

The Cygwin environment is special in that it supports both the native 
Windows API's and Linux/POSIX emulation API's.

The default for Boost.Filesystem builds is to treat Cygwin environment 
as  native Windows. Some Cygwin users would prefer the Linux/POSIX 
emulation.

Boost.Filesystem has now been tested in both Cygwin environments. No 
changes were required in the 1.31.0 or current CVS head implementation 
code. Two of the test programs have been changed in CVS to make testing 
both Cygwin environments easier.

The docs in CVS have been updated with the following "Notes for Cygwin 
users":

The library's implementation code automatically detects the current 
platform, and compiles the POSIX or Windows implementation code 
accordingly. Automatic platform detection during object library compilation 
can be overridden by defining BOOST_POSIX or BOOST_WINDOWS macros. With the 
exception of the Cygwin environment, there is usually no reason to define 
one of the macros, as the software development kits supplied with most 
compilers only support a single platform.

The Cygwin package of tools supports traditional Windows usage, but also 
provides an emulation layer and other tools which can be used to make 
Windows act as Linux (and thus POSIX), and provide the Linux look-and-feel. 
GCC is usually the compiler of choice in this environment, as it can be 
installed via the Cygwin install process. Other compilers can also use the 
Cygwin emulation of POSIX, at least in theory.

Those wishing to use the Cygwin POSIX emulation layer should define the 
BOOST_POSIX macro when compiling the Boost Filesystem Library's 
object-library. The macro does not need to be defined (and will have no 
effect if defined) for Boost Filesystem Library user programs.

--Beman