boost pool example

#include <new>
#include <boost/pool/singleton_pool.hpp>

class Data {
public:
    Data(int first) {
        data[0] = first;
    }

    Data(int first, int second) {
        data[0] = first;
        data[1] = second;
    }

    void* operator new(size_t x);

    void* operator new(size_t x, const std::nothrow_t& nothrow_value) throw();

    void operator delete(void* ptr);

private:
    int data[10];
};

class DataTag;

typedef boost::singleton_pool<DataTag, sizeof(Data)> DataPool;

void* Data::operator new(size_t x) {
    void* ptr = DataPool::malloc();
    if (ptr) {
        return ptr;
    } else {
        throw std::bad_alloc();
    }
}

void* Data::operator new(size_t x, const std::nothrow_t& nothrow_value) throw() {
    return DataPool::malloc();
}

void Data::operator delete(void* ptr) {
    DataPool::free(ptr);
}

int main() {
    Data* data = new Data(1);
    delete data;
    data = new (std::nothrow) Data(1, 2);
    delete data;
}