cmake_minimum_required (VERSION 3.13)
project(TLS)

#set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

#set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
#set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall")
#set(CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
#set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3 -march=native")
#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3 -march=native")
#set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Wall")

message( "========================\n")


include_directories(
${PROJECT_SOURCE_DIR}/include
)

message(${PROJECT_SOURCE_DIR}/include
)

file(GLOB SOURCES  "include/*.h" "src/*.cpp")



add_executable(${PROJECT_NAME}  ${SOURCES})

#target_link_libraries (${PROJECT_NAME} )
---------------------------------
//header.h
#ifndef HEADER_H
#define HEADER_H

#include <iostream>
#include <vector>

template<typename T>
T mone(T & data);

#endif
-----------------------------------
//header.cpp
#include "header.h"

template<typename T>
T mone(T & data)
{
    return -data;
}
  
----------------------


#include "header.h"

int main(void)
{


    int t1 = 25;
    std::cout << mone(t1) << std::endl;
    std::cout << t1 << std::endl;

    std::vector<int> a(1); // only a reminder telling running is done.
    std::cout << a[2] << std::endl;

    return 0;
}
---------------
错误：
2>main.obj : error LNK2019: unresolved external symbol "int __cdecl mone<int>(int &)" (??$mone@H@@YAHAAH@Z) referenced in function _main
build\Debug\TLS.exe : fatal error LNK1120: 1 unresolved externals
--
修改:scanworld FROM 106.39.0.*
FROM 106.39.0.*

谢谢
【 在 milksea 的大作中提到: 】
: 模板函数要放头文件里面
--
FROM 106.39.0.*