c++ - 当我尝试抛出异常时没有匹配函数错误

Question

我有这个代码:

class RepoException
{

public:

    RepoException(string& msg)
    {
        this->msg=msg;
    }

    string& getMsg()
    {
        return this->msg;
    }

private:

    string msg;
};

template<typename T>
class Repo 
{

public:

    Repo()
    {
        vector<T> elems;
    }

    void store(T elem) throw (RepoException)
    {
        for(int i =0; i<elems.size();i++)
        {
            if (elems[i]->getId() == elem->getId())
            {
                throw RepoException("There is a person with same id ");
            }

        }
        elems.push_back(elem);
    }

在函数 store 中，当我尝试抛出异常时出现此错误:

  Multiple markers at this line
    - candidates are:
    - no matching function for call to 'RepoException::RepoException(const 

为什么会出现此错误？

Answer 1

通话中

RepoException( "There is a person with same id ")

参数“There is a person with same id”的类型是const char []。这不能用于转换成字符串，但如果你这样写就可以:

RepoException( const string& msg)

一个好的做法是从 std::exception 派生异常，即 std::runtime_error .