命名空间“std”中的错误“underlying_type_t”未在项目 OSRM 的 example.cpp 中命名模板类型

Question

我尝试执行Project-OSRM的examle.cpp文件。我做了以下步骤：

• 按照此处所述从源代码构建 OSRM
• 在新终端中：cd osrm-backend/example
• 在终端中： cmake ..
• 在终端中： cmake --build 。
• 在终端中： sudo cmake --build 。--目标安装
• 移动地图承包商，发动机，提取，分割，储存，UTIL从在/ usr /本地/包括/ OSRM到在/ usr /本地/包括（否则错误的地图是不是在/ usr /本地/包括）
• 在终端中： g++ -std=c++11 example.cpp -o example

但我得到了错误

‘underlying_type_t’ in namespace ‘std’ does not name a template type
     static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>

有谁知道我做错了什么或出了什么问题以及如何解决这个问题？

错误信息

In file included from /usr/local/include/engine/api/match_parameters.hpp:31:0,
                 from /usr/local/include/osrm/match_parameters.hpp:31,
                 from example.cpp:1:
/usr/local/include/engine/api/route_parameters.hpp: In function ‘bool osrm::engine::api::operator&(osrm::engine::api::RouteParameters::AnnotationsType, osrm::engine::api::RouteParameters::AnnotationsType)’:
/usr/local/include/engine/api/route_parameters.hpp:144:26: error: ‘underlying_type_t’ in namespace ‘std’ does not name a template type
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(l
                          ^
/usr/local/include/engine/api/route_parameters.hpp:144:43: error: expected ‘>’ before ‘<’ token
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(l
                                           ^
/usr/local/include/engine/api/route_parameters.hpp:144:43: error: expected ‘(’ before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:144:43: error: expected primary-expression before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:144:76: error: expected primary-expression before ‘>>’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(lhs) &
                                                                       ^
/usr/local/include/engine/api/route_parameters.hpp:145:26: error: ‘underlying_type_t’ in namespace ‘std’ does not name a template type
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(r
                          ^
/usr/local/include/engine/api/route_parameters.hpp:145:43: error: expected ‘>’ before ‘<’ token
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(r
                                           ^
/usr/local/include/engine/api/route_parameters.hpp:145:43: error: expected ‘(’ before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:145:43: error: expected primary-expression before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:145:76: error: expected primary-expression before ‘>>’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(rhs));
                                                                       ^
/usr/local/include/engine/api/route_parameters.hpp:145:84: error: expected ‘)’ before ‘;’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(rhs));
                                                                               ^
/usr/local/include/engine/api/route_parameters.hpp:145:84: error: expected ‘)’ before ‘;’ token
/usr/local/include/engine/api/route_parameters.hpp: In function ‘osrm::engine::api::RouteParameters::AnnotationsType osrm::engine::api::operator|(osrm::engine::api::RouteParameters::AnnotationsType, osrm::engine::api::RouteParameters::AnnotationsType)’:
/usr/local/include/engine/api/route_parameters.hpp:152:26: error: ‘underlying_type_t’ in namespace ‘std’ does not name a template type
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(l
                          ^
/usr/local/include/engine/api/route_parameters.hpp:152:43: error: expected ‘>’ before ‘<’ token
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(l
                                           ^
/usr/local/include/engine/api/route_parameters.hpp:152:43: error: expected ‘(’ before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:152:43: error: expected primary-expression before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:152:76: error: expected primary-expression before ‘>>’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(lhs) |
                                                                       ^
/usr/local/include/engine/api/route_parameters.hpp:153:26: error: ‘underlying_type_t’ in namespace ‘std’ does not name a template type
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(r
                          ^
/usr/local/include/engine/api/route_parameters.hpp:153:43: error: expected ‘>’ before ‘<’ token
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(r
                                           ^
/usr/local/include/engine/api/route_parameters.hpp:153:43: error: expected ‘(’ before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:153:43: error: expected primary-expression before ‘<’ token
/usr/local/include/engine/api/route_parameters.hpp:153:76: error: expected primary-expression before ‘>>’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(rhs));
                                                                       ^
/usr/local/include/engine/api/route_parameters.hpp:153:84: error: expected ‘)’ before ‘;’ token
    static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(rhs));
                                                                               ^
/usr/local/include/engine/api/route_parameters.hpp:153:84: error: expected ‘)’ before ‘;’ token

Answer 1

underlying_type_t需要 C++14。为了能够使用它传递-std=c++14给你的编译器。