使用 date_time_formatter 时 Boost 日志库的编译错误

Question

我正在尝试使用 Boost 日志库，并且想在输出中添加时间戳。我从this example 开始，但遇到了编译错误。我完全按照示例复制了代码，并将init() 函数更改为第二个函数（example_tutorial_formatters_stream_date_time）。现在我有以下编译错误：

$ g++ -Wall -Wextra -O0 -g -isystem /proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include -c main.cpp -o main.o
In file included from /proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include/boost/log/expressions/formatters.hpp:23:0,
                 from /proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include/boost/log/expressions.hpp:26,
                 from main.cpp:109:
/proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include/boost/log/expressions/formatters/date_time.hpp: In instantiation of 'boost::log::v2s_mt_posix::expressions::format_date_time_terminal<T, FallbackPolicyT, CharT>::format_date_time_terminal(const boost::log::v2s_mt_posix::attribute_name&, const fallback_policy&, const string_type&) [with T = boost::posix_time::ptime; FallbackPolicyT = boost::log::v2s_mt_posix::fallback_to_none; CharT = char; boost::log::v2s_mt_posix::expressions::format_date_time_terminal<T, FallbackPolicyT, CharT>::fallback_policy = boost::log::v2s_mt_posix::fallback_to_none; boost::log::v2s_mt_posix::expressions::format_date_time_terminal<T, FallbackPolicyT, CharT>::string_type = std::basic_string<char>]':
/proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include/boost/log/expressions/formatters/date_time.hpp:229:94:   required from 'boost::log::v2s_mt_posix::expressions::format_date_time_actor<AttributeValueT, boost::log::v2s_mt_posix::fallback_to_none, CharT> boost::log::v2s_mt_posix::expressions::format_date_time(const boost::log::v2s_mt_posix::attribute_name&, const CharT*) [with AttributeValueT = boost::posix_time::ptime; CharT = char]'
main.cpp:156:103:   required from here
/proj/cudbdm/tools/external/boost/inst_1_54_0_cxx11/include/boost/log/expressions/formatters/date_time.hpp:94:68: error: incomplete type 'boost::log::v2s_mt_posix::expressions::format_date_time_terminal<boost::posix_time::ptime, boost::log::v2s_mt_posix::fallback_to_none, char>::formatter_generator {aka boost::log::v2s_mt_posix::expressions::aux::date_time_formatter_generator_traits<boost::posix_time::ptime, char, void>}' used in nested name specifier
         m_name(name), m_formatter(formatter_generator::parse(format)), m_visitor_invoker(fallback)
                                                                    ^

我尝试使用带有和不带有-std=c++11 标志的 gcc 4.7.2 和 4.8.1，但每次都得到相同的结果。似乎错误在Boost库中，这对我来说很奇怪，因为即使是官方示例也无法编译。

Answer 1

问题是需要包含<boost/log/support/date_time.hpp>。它也在文档中的适当位置进行了说明，但不知何故被排除在示例之外。