collect2.exe: error: ld returned 1 exit status

￡神魔★判官ぃ 2023-02-18 01:59 26阅读 0赞

程序运行时报错collect2.exe: error: ld returned 1 exit status

c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Temp\ccnQ8uo7.o:ex2.2.cpp:(.text+0xbb): undefined reference to `displayMessage(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<int, std::allocator<int> > const&)'
    collect2.exe: error: ld returned 1 exit status
    [Finished in 0.6s with exit code 1]

#include <iostream>
    #include <vector>
    
    using namespace std;
    
    const int maxSize = 1024;
    void displayMessage(const string &msg, const vector<int> &vec);
    const vector<int>* Pentagonal(int size);
    
    int main(int argc, char const *argv[])
    { 
    	int pos;
    
    	cout << "Please enter a positon: ";
    	cin >> pos;
    
    	if (pos <= 0 || pos > maxSize)
    	{ 
    		cout << "Requested size is not supported!" << endl;
    		return -1;
    	}
    	
    	displayMessage("Pentagonal:", *(Pentagonal(pos)));
    
    	return 0;
    }
    
    template <typename elemType>
    void displayMessage(const string &msg, const vector<elemType> &vec)
    { 
    	cout << msg;
    	for (int i = 0; i < vec.size(); ++i)
    	{ 
    		elemType t = vec[i];
    		cout << t << ' ';
    	}
    }
    
    const vector<int>* Pentagonal(int size)
    { 
    	static vector<int> elems;
    	const string msg("Requested size is not supported ");
    
    
    	if (size <= 0 || size > maxSize)
    	{ 
    		cout << "Requested size is not supported!" << endl;
    		return 0;
    	}
    
    	for (int i = elems.size(); i < size; ++i)
    		elems.push_back((i + 1) * (3 * i + 2) / 2);
    	
    	return &elems;
    }

[参考了原博客][Link 1]，应该是函数声明和实现之间存在问题，不了解具体原因，将函数实现提前了，然后不再报错。

#include <iostream>
    #include <vector>
    
    using namespace std;
    
    const int maxSize = 1024;
    
    template <typename elemType>
    void displayMessage(const string &msg, const vector<elemType> &vec)
    { 
    	cout << msg;
    	for (int i = 0; i < vec.size(); ++i)
    	{ 
    		elemType t = vec[i];
    		cout << t << ' ';
    	}
    }
    
    const vector<int>* Pentagonal(int size)
    { 
    	static vector<int> elems;
    
    	if (size <= 0 || size > maxSize)
    	{ 
    		cout << "Requested size is not supported!" << endl;
    		return 0;
    	}
    
    	for (int i = elems.size(); i < size; ++i)
    	{ 
    		elems.push_back((i + 1) * (3 * i + 2) / 2);
    	}
    	return &elems;
    }
    
    
    int main(int argc, char const *argv[])
    { 
    	int pos;
    
    	cout << "Please enter a positon: ";
    	cin >> pos;
    
    	if (pos <= 0 || pos > maxSize)
    	{ 
    		cout << "Requested size is not supported!" << endl;
    		return -1;
    	}
    	
    	displayMessage("Pentagonal:", *(Pentagonal(pos)));
    
    	return 0;
    }

先声明后调用的模式该怎么解决，暂时还没有想法。

[Link 1]: https://blog.csdn.net/u013232456/article/details/82346310?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase