知道这条消息是什么意思吗？我正在使用 gcc 4.9 编译sqangle。
In file included from /home/ubuntu/Devel/hhvm/third-party/squangle/squangle/mysql_client/Row.cpp:10:0:
/home/ubuntu/Devel/hhvm/third-party/squangle/src/squangle/mysql_client/Row.h:171:6: error: ‘chrono’ in namespace ‘std’ does not name a type
std::chrono::system_clock::time_point parseDateTime(StringPiece datetime,
^
/home/ubuntu/Devel/hhvm/third-party/squangle/src/squangle/mysql_client/Row.h:174:6: error: ‘chrono’ in namespace ‘std’ does not name a type
std::chrono::microseconds parseTimeOnly(StringPiece mysql_time,
^
/home/ubuntu/Devel/hhvm/third-party/squangle/src/squangle/mysql_client/Row.h:354:6: error: ‘chrono’ in namespace ‘std’ does not name a type
std::chrono::system_clock::time_point RowBlock::getField(
^
/home/ubuntu/Devel/hhvm/third-party/squangle/src/squangle/mysql_client/Row.h:358:6: error: ‘chrono’ in namespace ‘std’ does not name a type
std::chrono::microseconds RowBlock::getField(size_t row,
^
/home/ubuntu/Devel/hhvm/third-party/squangle/squangle/mysql_client/Row.cpp: In member function ‘T facebook::common::mysql_client::RowBlock::getField(size_t, size_t) const [with T …