将 boost 与 Visual Studio 和 vcpkg 链接时出错

Question

我正在尝试完成一项简单的任务，以检查在Windows中开发"Linux应用程序"的难易程度。

我正在使用 Microsoft 的 vcpkg 来设置标头、库和 crow，一个使用 boost 作为驱动程序项目的 c++ http 服务器

来源很简单

#include "crow.hpp"
int main()
{
crow::SimpleApp app;
CROW_ROUTE(app, "/")
([]() {
return "Hello world!";
});
app.port(18080).run();
}

我已经通过vcpkg下载了boost，并使用Visual Studio对项目进行了编码

cmake：

cmake_minimum_required (VERSION 3.8)
find_package(boost COMPONENTS  filesystem system thread date_time REQUIRED)
message("this is ${Boost_INCLUDE_DIRS}")
include_directories ("C:\github.com\crow\include")
include_directories(SYSTEM PUBLIC ${Boost_INCLUDE_DIRS})
add_executable (engine "promo-engine-windows.cpp" "promo-engine-windows.h")
target_link_libraries(engine  ${Boost_LIBRARIES})

CMakeSettings.json

{
"configurations": [
{
"name": "x86-Debug",
"generator": "Visual Studio 15 2017",
"configurationType": "Debug",
"buildRoot": "${env.USERPROFILE}\CMakeBuilds\${workspaceHash}\build\${name}",
"cmakeCommandArgs": "",
"buildCommandArgs": "-m -v:minimal",
"variables": [
{
"name": "CMAKE_TOOLCHAIN_FILE",
"value": "C:\github.com\vcpkg\scripts\buildsystems\vcpkg.cmake"
}
]
}
]
}

链接会产生错误：

error LNK2019: unresolved external symbol "__declspec(dllimport) class boost::system::error_category const & __cdecl boost::system::system_category(void)" (__imp_?system_category@system@boost@@YAABVerror_category@12@XZ) referenced in function "public: __thiscall boost::system::error_code::error_code(void)" (??0error_code@system@boost@@QAE@XZ) 
error LNK2019: unresolved external symbol "__declspec(dllimport) class boost::system::error_category const & __cdecl boost::system::generic_category(void)" (__imp_?generic_category@system@boost@@YAABVerror_category@12@XZ) referenced in function "public: virtual bool __thiscall boost::system::error_category::std_category::equivalent(class std::error_code const &,int)const " (?equivalent@std_category@error_category@system@boost@@UBE_NABVerror_code@std@@H@Z) 
error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall boost::gregorian::greg_month::greg_month(unsigned short)" (__imp_??0greg_month@gregorian@boost@@QAE@G@Z) referenced in function "public: __thiscall boost::gregorian::date::date(enum boost::date_time::special_values)" (??0date@gregorian@boost@@QAE@W4special_values@date_time@2@@Z) 
error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall boost::gregorian::greg_month::operator unsigned short(void)const " (__imp_??Bgreg_month@gregorian@boost@@QBEGXZ) referenced in function "public: static unsigned int __cdecl boost::date_time::gregorian_calendar_base<struct boost::date_time::year_month_day_base<class boost::gregorian::greg_year,class boost::gregorian::greg_month,class boost::gregorian::greg_day>,unsigned int>::day_number(struct boost::date_time::year_month_day_base<class boost::gregorian::greg_year,class boost::gregorian::greg_month,class boost::gregorian::greg_day> const &)" (?day_number@?$gregorian_calendar_base@U?$year_month_day_base@Vgreg_year@gregorian@boost@@Vgreg_month@23@Vgreg_day@23@@date_time@boost@@I@date_time@boost@@SAIABU?$year_month_day_base@Vgreg_year@gregorian@boost@@Vgreg_month@23@Vgreg_day@23@@23@@Z) 
fatal error LNK1120: 4 unresolved externals 
Build failed

它给任何人敲响了警钟吗？我为此苦苦挣扎了几个小时。

Answer 1

您应该更改 cmake 文件以完全匹配 https://github.com/Microsoft/vcpkg/blob/master/ports/boost/usage。

例如，find_package包名称应该是 Boost 而不是 boost，如果未找到 boost，添加 REQUIRED 会使它失败，cmake 可能找不到 boost 并默默忽略它。