dlib C++ Library - std_allocator_ex.cpp

    /*
        This is an example illustrating the use of the dlib::std_allocator object.

        In this example we will create the necessary typedefs to give the
        dlib::std_allocator object to the standard string and vector objects
        in the STL.  Thus we will create versions of std::string and std::vector
        that perform all their memory allocations and deallocations via one of
        the dlib memory manager objects.
    */

    // include everything we need for this example
    #include <vector>
    #include <iostream>
    #include <string>
    #include "dlib/std_allocator.h"
    #include "dlib/memory_manager.h"
    #include "dlib/memory_manager_stateless.h"

    using namespace std;
    using namespace dlib;

    int main()
    {
        // Make a typedef for an allocator that uses the thread safe memory_manager_stateless object with a
        // global memory pool.  This version of the memory_manager_stateless object keeps everything it allocates
        // in a global memory pool and doesn't release any memory until the program terminates.
        typedef std_allocator<char, memory_manager_stateless<char>::kernel_2_3a> alloc_char_with_global_memory_pool;

        // Now make a typedef for a C++ standard string that uses our new allocator type
        typedef std::basic_string<char, char_traits<char>, alloc_char_with_global_memory_pool > dstring;

        // typedef another allocator for dstring objects
        typedef std_allocator<dstring, memory_manager_stateless<char>::kernel_2_3a> alloc_dstring_with_global_memory_pool;

        // Now make a typedef for a C++ standard vector that uses our new allocator type and also contains the new dstring
        typedef std::vector<dstring, alloc_dstring_with_global_memory_pool > dvector;

        // Now we can use the string and vector we have as we normally would.  So for example, I can make a
        // dvector and add 4 strings into it like so:
        dvector v;
        v.push_back("one");
        v.push_back("two");
        v.push_back("three");
        v.push_back("four");

        // And now we print out the contents of our vector
        for (unsigned long i = 0; i < v.size(); ++i)
        {
            cout << v[i] << endl;
        }

    }