Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859

@echo off
set VS10=%ProgramFiles(x86)%\Microsoft Visual Studio 10.0
IF EXIST "%VS10%" GOTO ok
set VS10=%ProgramFiles%\Microsoft Visual Studio 10.0
:ok

echo Build environments: x86, ia64, amd64, x86_amd64, x86_ia64
echo.
call "%VS10%\VC\vcvarsall.bat" %1