将元组行集与最新的 soci 和 boost 库一起使用时出现编译错误。
我在网上找到了一个示例,但它不能与我使用的最新版本的 SOCI 编译。
导致问题的部分是这个:
typedef std::vector<boost::tuple<double, double> > V;
soci::rowset<boost::tuple<double, double> > rows
= sql.prepare << "select x(location),y(location) from cities";
这是我从网上的一个例子中得到的完整代码:
#include <soci.h>
#include <soci-postgresql.h>
#include <boost/algorithm/string.hpp>
#include <boost/optional.hpp>
#include <boost/timer.hpp>
#include <boost/random.hpp>
#include <boost/tuple/tuple.hpp>
#include <iostream>
#include <istream>
#include <ostream>
#include <sstream>
#include <string>
#include <exception>
int main()
{
try
{
soci::session sql(soci::postgresql, "dbname=ggl user=ggl password=ggl");
int count;
sql << "select count(*) from cities", soci::into(count);
std::cout << "# Capitals: " << count << std::endl;
typedef std::vector<boost::tuple<double, double> > V;
soci::rowset<boost::tuple<double, double> > rows
= sql.prepare << "select x(location),y(location) from cities";
V vec;
std::copy(rows.begin(), rows.end(), std::back_inserter(vec));
for (V::const_iterator it = vec.begin(); it != vec.end(); ++it)
{
std::cout << it->get<0>() << " " << it->get<1>() << std::endl;
}
}
catch (std::exception const &e)
{
std::cerr << "Error: " << e.what() << '\n';
}
return 0;
}
它在以下行失败:
soci::rowset<boost::tuple<double, double> > rows
= sql.prepare << "select x(location),y(location) from cities";
这是我不太明白的错误:
g++ -c "/home/ubuntu/dev/testSoci/test.cpp" -g -O0 -Wall -o ./Debug/test.o -I./include -I/home/ubuntu/dev/tools/QxOrm/include -I/usr/share/qt4/include -I/home/ubuntu/dev/tools/boost_1_48_0 -I. -I. -I/home/ubuntu/dev/tools/soci-3.1.0/core -I/home/ubuntu/dev/tools/soci-3.1.0/backends/postgresql -I/usr/include/postgresql -I/home/ubuntu/dev/tools/boost_1_48_0/boost
In file included from /home/ubuntu/dev/tools/soci-3.1.0/core/into-type.h:13,
from /home/ubuntu/dev/tools/soci-3.1.0/core/blob-exchange.h:12,
from /home/ubuntu/dev/tools/soci-3.1.0/core/soci.h:18,
from /home/ubuntu/dev/testSoci/test.cpp:21:
/home/ubuntu/dev/tools/soci-3.1.0/core/exchange-traits.h: In instantiation of ‘soci::details::exchange_traits<boost::tuples::tuple<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >’:
/home/ubuntu/dev/tools/soci-3.1.0/core/into.h:29: instantiated from ‘soci::details::into_type_ptr soci::into(T&) [with T = boost::tuples::tuple<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]’
/home/ubuntu/dev/tools/soci-3.1.0/core/rowset.h:125: instantiated from ‘soci::details::rowset_impl<T>::rowset_impl(const soci::details::prepare_temp_type&) [with T = boost::tuples::tuple<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]’
/home/ubuntu/dev/tools/soci-3.1.0/core/rowset.h:185: instantiated from ‘soci::rowset<T>::rowset(const soci::details::prepare_temp_type&) [with T = boost::tuples::tuple<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]’
/home/ubuntu/dev/testSoci/test.cpp:51: instantiated from here
/home/ubuntu/dev/tools/soci-3.1.0/core/exchange-traits.h:34: error: incomplete type ‘soci::details::exchange_traits<boost::tuples::tuple<double, double, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >’ used in nested name specifier
make[1]: *** [Debug/test.o] Error 1
知道可能是什么原因吗?
非常感谢!卢多维奇
一个解决方案是
1/ 添加括号 soci::rowset > rows = (sql.prepare << "select x(location),y(location) from cities");
2/ 执行建议的答案:#include 或 #define