问题
I'm trying to display an image file in the browser through a boost beast http server. Using the example from here I wrote the following:
#include <iostream>
#include <string>
#include <memory>
#include <thread>
#include <cstdlib>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/core/core.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/config.hpp>
using boost::asio::ip::tcp;
namespace http = boost::beast::http;
int main(){
try{
boost::asio::io_context io_service;
tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 1112));
boost::system::error_code err;
boost::beast::flat_buffer buffer;
bool close = false;
http::file_body::value_type body;
std::string path = "./x.jpg";
for (;;){
tcp::socket socket(io_service);
acceptor.accept(socket);
body.open(path.c_str(), boost::beast::file_mode::scan, err);
auto const size = body.size();
http::request<http::string_body> req;
http::read(socket, buffer, req, err);
if(err)
std::cerr << "read: " << err.message() << "\n";
if(req.method() == http::verb::head){
http::response<http::empty_body> res{http::status::ok, req.version()};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, "image/jpeg");
res.content_length(size);
res.keep_alive(req.keep_alive());
http::write(socket, res, err);
}
http::response<http::file_body> res{std::piecewise_construct,
std::make_tuple(std::move(body),
std::make_tuple(http::status::ok, req.version()))};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, "image/jpeg");
res.content_length(size);
res.keep_alive(req.keep_alive());
http::write(socket, res, err);
}
}
catch(std::exception& e)
{
std::cerr << e.what() << std::endl;
return EXIT_FAILURE;
}
return 0;
}
I'm trying to compile it using
g++ -std=c++11 bs2.cpp -o bs2 -lpthread -lboost_system `pkg-config opencv --cflags --libs`
But I can't make sense of the following error I'm getting:
In file included from /usr/include/boost/beast/core/multi_buffer.hpp:15:0,
from /usr/include/boost/beast/core/buffered_read_stream.hpp:15,
from /usr/include/boost/beast/core.hpp:16,
from bs2.cpp:12:
/usr/include/boost/beast/core/detail/empty_base_optimization.hpp: In instantiation of ‘boost::beast::detail::empty_base_optimization<T, UniqueID, false>::empty_base_optimization(Arg1&&, ArgN&& ...) [with Arg1 = boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type; ArgN = {std::tuple<boost::beast::http::status, unsigned int>}; T = boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type; int UniqueID = 0]’:
/usr/include/boost/beast/http/message.hpp:908:51: required from ‘boost::beast::http::message<<anonymous>, <template-parameter-1-2>, <template-parameter-1-3> >::message(std::piecewise_construct_t, std::tuple<_Args1 ...>&, boost::beast::detail::index_sequence<S ...>) [with BodyArgs = {boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type, std::tuple<boost::beast::http::status, unsigned int>}; long unsigned int ...IBodyArgs = {0, 1}; bool isRequest = false; Body = boost::beast::http::basic_file_body<boost::beast::file_posix>; Fields = boost::beast::http::basic_fields<std::allocator<char> >; boost::beast::detail::index_sequence<S ...> = boost::beast::detail::integer_sequence<long unsigned int, 0, 1>]’
/usr/include/boost/beast/http/impl/message.ipp:299:35: required from ‘boost::beast::http::message<<anonymous>, <template-parameter-1-2>, <template-parameter-1-3> >::message(std::piecewise_construct_t, std::tuple<_Args1 ...>) [with BodyArgs = {boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type, std::tuple<boost::beast::http::status, unsigned int>}; bool isRequest = false; Body = boost::beast::http::basic_file_body<boost::beast::file_posix>; Fields = boost::beast::http::basic_fields<std::allocator<char> >]’
bs2.cpp:90:66: required from here
/usr/include/boost/beast/core/detail/empty_base_optimization.hpp:81:40: error: no matching function for call to ‘boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type::value_type(boost::beast::http::basic_file_body<boost::beast::file_posix>::value_type, std::tuple<boost::beast::http::status, unsigned int>)’
std::forward<ArgN>(argn)...)
^
In file included from /usr/include/boost/beast/http/file_body.hpp:14:0,
from /usr/include/boost/beast/http.hpp:24,
from bs2.cpp:13:
/usr/include/boost/beast/http/basic_file_body.hpp:110:5: note: candidate: boost::beast::http::basic_file_body<File>::value_type::value_type(boost::beast::http::basic_file_body<File>::value_type&&) [with File = boost::beast::file_posix]
value_type(value_type&& other) = default;
^~~~~~~~~~
/usr/include/boost/beast/http/basic_file_body.hpp:110:5: note: candidate expects 1 argument, 2 provided
/usr/include/boost/beast/http/basic_file_body.hpp:107:5: note: candidate: constexpr boost::beast::http::basic_file_body<File>::value_type::value_type() [with File = boost::beast::file_posix]
value_type() = default;
^~~~~~~~~~
/usr/include/boost/beast/http/basic_file_body.hpp:107:5: note: candidate expects 0 arguments, 2 provided
On my last post I was told to use boost beast. This was my attempt. I'm only writing this because my question is mostly code and I'm not being allowed to post it but I can't be any more descriptive because I can't even understand the source of the error.
Any help/advice would be appreciated. Cheers!
来源：https://stackoverflow.com/questions/58447312/erroneous-implementation-of-boost-beast-sync-http-server