[cfe-dev] libcxx install location?

[Larry Evans]

After failing to use libstdc++:
  http://lists.cs.uiuc.edu/pipermail/cfe-dev/2011-February/013216.html
I tried to understand how to use libc++:
  http://libcxx.llvm.org/
Although that libcxx page mentions:
  clang++ -stdlib=libc++ test.cpp
there's no mention of this opton here:
  http://clang.llvm.org/docs/UsersManual.html#commandline
Also, that libcxx page makes no mention of:
  http://llvm.org/svn/llvm-project/cfe/trunk/runtime/libcxx/Makefile
However, seeing:
  LIBCXX_SRC_ROOT := $(LLVM_SRC_ROOT)/projects/libcxx
  CPP.Flags := -nostdinc++ -I$(LIBCXX_SRC_ROOT)/include
in that Makefile, suggests that maybe one option is to install libcxx
below my svn working directory:
  ~/download/llvm/svn/llvm/tools/clang/runtime
with something like:
  svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx
from within that svn working directory.  In that case, would there be
any need for the -stdlib=libc++ option to clang++?  But then what
arguments should I pass ~/download/llvm/svn/llvm/configure to cause
the libcxx library to be built? Grepping that configure for libcxx
showed nothing.

TIA for any help.

-regards,
Larry