我想在共享内存中使用Boost进程库创建一个unordered_map。这里,是代码,这是我想要使用(以从升压进程间文件的例子):boost进程间unordered_map字符串
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <functional>
#include <boost/functional/hash.hpp>
#include <boost/unordered_map.hpp>
#include <iostream>
#include <string>
#include <boost/interprocess/containers/string.hpp>
namespace bipc = boost::interprocess;
typedef bipc::allocator<char, bipc::managed_shared_memory::segment_manager> CharAllocator;
typedef bipc::basic_string<char, std::char_traits<char>, CharAllocator> ShmemString;
struct Person
{
int age;
ShmemString name;
double salary;
Person(int i,
double sal,
const char* s,
const char_allocator& a)
: age(i),
name(s, a),
salary(sal)
{
}
void print() {}
}
typedef ShmemString KeyType;
typedef Person MappedType;
typedef std::pair< KeyType, MappedType > MapPersonType;
typedef bipc::allocator< MapPersonType,
bipc::managed_shared_memory::segment_manager >
ShMemAllocator;
typedef boost::unordered_map< KeyType,
MappedType,
boost::hash<KeyType>,
std::equal_to<KeyType>,
ShMemAllocator >
PersonMap;
这就是我想在主程序中要做到:
int main()
{
bipc::managed_shared_memory segment(bipc::create_only, "MySharedMemory", 65536);
PersonMap *persons = segment.construct<PersonMap>("MyHashMap")
(3, boost::hash<ShmemString>(), std::equal_to<ShmemString>()
, segment.get_allocator<MapPersonType>());
char_allocator alloc(segment.get_allocator<char>());
Person p1(20, 10000, "ABC", alloc);
persons->insert(MapPersonType(ShmemString("Person1", alloc), p1));
}
使用上面的代码,我可以在共享内存中创建一个unordered_map。然而,当我试图访问地图,我需要使用像
persons->at(ShmemString("H", segment.get_allocator<char>())).print();
语法但是,我宁愿用的std :: string,这会导致编译错误做到这一点:
persons->at(std::string("H")).print();
是否有可能编写上述语句,即使用std :: string访问共享内存中分配的映射?
我发布在boost-users邮件列表上。并且,从Boost.Interprocess作者那里得到了一个答案,这是无法完成的。 – Lazylabs 2013-03-15 16:00:58