Re: small problem with auto (c++0x)

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

On 5 May 2012 00:04, Amit Markel wrote:
> Hello, please consider the little program below which was compiled on GCC 4.7.0.

Your question is inappropriate on this list which is for discussing
development of GCC not with GCC.  Your question would be appropriate
on the gcc-help list, please take any follow up there, thanks.

> /* ? ? ? ? ? ? ?auto */ vector<int> arr = {i,i+1,i+2};

With 'auto' here the type is not vector<int>, it's
std::initializer_list<int>, which is a lightweight utility type that
refers to a temporary array. An initializer_list is intended to be
used only as a temporary or other short-lived type.

In your code the initializer_list gets copied into the std::thread,
but then the temporary array it uses goes out of scope. When the add()
function runs a std::vector is constructed from the initializer_list,
copying the data from the invalid array that has already gone out of
scope.