Using CMake targets in Visual Studio projects - c++

Question

I am pretty comfortable with CMake when used in Linux. That is, I use CMake to logically group my code into "targets" and abstract such things as "include directories" and other dependencies. Say, inside a large project my modus operandi would be to add_library(..SHARED) for a bunch of related files that provide one logically coherent unit, and target_link_libraries(...) to it from somewhere else.
(Of course, idiosyncrasies of CMake is another topic. I won't digress to discussions about e.g. its syntax.)
Now, for Windows 10. I fired up Visual Studio 2019 Community with the MSVC toolchain (that is, not WSL/WSL2), and created a CMake Project using VS's "New Project" wizard.
It has created for me some boilerplate code, and the whole project tree looks as below:
In this image, EnRouteGeneratedLibrary is something I added as the next step. Inside it, I have one *.hpp file:
#pragma once
template<typename T>
class __declspec(dllexport) SampleTemplateKlass {
public:
T sum(T x, T y) { return x + y; }
};
template class __declspec(dllexport) SampleTemplateKlass<int>;
and the CMakeLists.txt's contents are as follows:
add_library(${TRG} SHARED ${CMAKE_CURRENT_SOURCE_DIR}/SampleTemplateKlass.hpp)
# set_target_sources(${TRG} PUBLIC SampleTemplateKlass.hpp)
set_target_properties(${TRG} PROPERTIES LINKER_LANGUAGE CXX)
target_include_directories(${TRG} PUBLIC .)
set(WINDOWS_EXPORT_ALL_SYMBOLS 1)
Finally, in when building a simple "Hello World" executable, I have the following:
//
#include "SampleProjectWithDll.h"
#include "SampleTemplateKlass.hpp"
using namespace std;
int main()
{
cout << "Hello CMake." << endl;
SampleTemplateKlass<int> tmp;
std::cout << tmp.sum(42, 314) << std::endl;
return 0;
}
(This is the boilerplate code created by VS + my additions).
I link as follows:
# CMakeList.txt : CMake project for SampleProjectWithDll, include source and define
# project specific logic here.
#
cmake_minimum_required (VERSION 3.8)
add_subdirectory(EnRouteGeneratedLibrary)
# Add source to this project's executable.
add_executable (SampleProjectWithDll "SampleProjectWithDll.cpp" "SampleProjectWithDll.h")
target_link_libraries(SampleProjectWithDll PUBLIC SampleLibrary)
# TODO: Add tests and install targets if needed.
When building all this, I get two errors,
LNK2001 unresolved external symbol _DllMainCRTStartup and LNK1120 1 unresolved externalswith SampleLibrary.dll in the "File" field of the error panel.
The question is, how to make this simple "Hello World" compile and execute under Windows,
using the CMake infrastructure?