Question

The Boost.Pool documentation says that (emphasis mine):

The Boost Pool library is a header-only library. That means there is
no .lib, .dll, or .so to build; just add the Boost directory to your
compiler’s include file path, and you should be good to go!

But when I try to compile code like this in VS2010 SP1:

#include <string>
#include <vector>

#include <boost\pool\pool_alloc.hpp>

int main()
{
    typedef std::basic_string<wchar_t, std::char_traits<wchar_t>, 
        boost::pool_allocator<wchar_t>> PoolString;

    std::vector<PoolString> vec;
    for (int i = 0; i < 100; i++)
    {
        PoolString s(L"Some test string. ABCDEF.");
        vec.push_back(s);
    }

    // Release pool memory
    boost::singleton_pool<boost::pool_allocator_tag, sizeof(wchar_t)>::release_memory();

    return 0;
}

I got a linker error:

error LNK1104: cannot open file
‘libboost_thread-vc100-mt-gd-1_49.lib’

Is Boost.Pool documentation incorrect?
What am I missing here?
How can I use Boost.Pool?

Answer 1

The boost::singleton_pool is using a default mutex implementation that is located in boost::thread, which is not header only.

See the singleton_pool header quoted below for information on how to remove the dependency:

Mutex This class is the type of mutex to use to protect
simultaneous access to the underlying Pool. Can be any Boost.Thread
Mutex type or boost::details::pool::null_mutex. It is
exposed so that users may declare some singleton pools normally (i.e.,
with synchronization), but some singleton pools without
synchronization (by specifying
boost::details::pool::null_mutex) for efficiency reasons.
The member typedef mutex exposes the value of this template
parameter. The default for this parameter is
boost::details::pool::default_mutex which is a synonym for either
boost::details::pool::null_mutex (when threading support is
turned off in the compiler (so BOOST_HAS_THREADS is not set), or
threading support has ben explicitly disabled with
BOOST_DISABLE_THREADS (Boost-wide disabling of threads) or
BOOST_POOL_NO_MT (this library only)) or for boost::mutex
(when threading support is enabled in the compiler).