Re: [Boost-users] How to convert std::string into basic_string

I am trying to store the index file (keyword , position) where keyword is string while position is long. But before doing that i am doing some benchmarking for the given code in which map is created as key, value. Where key is char_string (typedef of basic_string) but when i read the data using C++, it will be string. So my intention is to convert string into char_string. For that i am testing to convert std:: string s = "test" into char_string. But getting the error message. Please do help me. #include #include #include #include #include #include <iostream> using namespace boost::interprocess; //Typedefs of allocators and containers typedef managed_shared_memory::segment_manager segment_manager_t; typedef allocator void_allocator; typedef allocator int_allocator; typedef vector int_vector; typedef allocator int_vector_allocator; typedef vector int_vector_vector; typedef allocator char_allocator; typedef basic_string char_string; class complex_data { int id_; char_string char_string_; int_vector_vector int_vector_vector_; public: //Since void_allocator is convertible to any other allocator<T>, we can simplify //the initialization taking just one allocator for all inner containers. complex_data(int id, const char *name, const void_allocator &void_alloc) : id_(id), char_string_(name, void_alloc), int_vector_vector_(void_alloc) {} //Other members... }; //Definition of the map holding a string as key and complex_data as mapped type typedef std::pair map_value_type; typedef std::pair movable_to_map_value_type; typedef allocator map_value_type_allocator; typedef map< char_string, int , std::less, map_value_type_allocator> complex_map_type; int main () { //Remove shared memory on construction and destruction struct shm_remove { shm_remove() { shared_memory_object::remove("MySharedMemory"); } ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); } } remover; //Create shared memory managed_shared_memory segment(create_only,"MySharedMemory", 65536); //An allocator convertible to any allocator type void_allocator alloc_inst (segment.get_segment_manager()); //Construct the shared memory map and fill it complex_map_type *mymap = segment.construct //(object name), (first ctor parameter, second ctor parameter) ("MyMap")(std::less(), alloc_inst); std::string s1("test"); char_string s2(s1.c_str()); for(int i = 0; i < 100; ++i) { char_string key_object(alloc_inst); map_value_type value(key_object, i); mymap->insert(value); } return 0; } Roland Bock-2 wrote:

Hi,

can you please send a small but complete sample code of what you are trying (a bunch of includes and a main function, not more than a few lines)?

Regards,

Roland

manish4gupta wrote:

...

I have tried both but i am getting the following error message

In constructor ‘boost::interprocess_container::basic_string::basic_string(const CharT*, const A&) [with CharT = char, Traits = std::char_traits<char>, A = boost::interprocess::allocator, boost::interprocess::iset_index>

...

]’: run.cpp:63: error: no matching function for call to ‘boost::interprocess::allocator, boost::interprocess::iset_index> ::allocator()’ /usr/include/boost/interprocess/allocators/allocator.hpp:129: note: candidates are: boost::interprocess::allocator::allocator(const boost::interprocess::allocator&) [with T = char, SegmentManager = boost::interprocess::segment_manager, boost::interprocess::iset_index>] /usr/include/boost/interprocess/allocators/allocator.hpp:124: note: boost::interprocess::allocator::allocator(SegmentManager*) [with T = char, SegmentManager = boost::interprocess::segment_manager, boost::interprocess::iset_index>]

Igor R wrote:

...

...

This is ok but i have to convert string into boost string. You mean Boost.Interprocess string.

std::string s1("test");

char_string s2(s1.begin(), s1.end()); or: char_string s2(s1.c_str()); _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

-- View this message in context: http://www.nabble.com/How-to-convert-std%3A%3Astring-into-basic_string-tp254... Sent from the Boost - Users mailing list archive at Nabble.com.