C++'da Txt'den satır satır okuma işlemi

#include <iostream>
#include <vector>
using std::cout;
using std::vector;
using std::string;
class File {
    private:
    FILE * fp;
    char * line = NULL;
    size_t len = 0;
    ssize_t read;
    string str;
    vector<string> stvec;
    bool ReadLine();
    public:
    File(FILE * fptr) {
        fp = fptr;
    }
    void printLines(size_t LineCount);
};
bool File::ReadLine() {
    if(fp == NULL ){
        return false;
    }
    while((read = getline(&line, &len, fp)) != -1) {
        str = line;
        stvec.push_back(str);
    }
    fclose(fp);
    if(line) {
        free(line);
    }
    return true;
}
void File::printLines(size_t  LineCount) {
    if(ReadLine()){
        if(LineCount <= 0) {
            exit(EXIT_FAILURE);
        }
        if(stvec.end() <= stvec.begin() + LineCount) {
            for(vector<string>::iterator i = stvec.begin(); i < stvec.end(); i++) {
                cout << * i << std::endl;
            }
        }
        if(stvec.end() > stvec.begin() + LineCount && LineCount > 0) {
            for(vector<string>::iterator i = stvec.begin(); i < (stvec.begin() + LineCount); i++) {
                cout << * i << std::endl;
            }
        }
    }
}
int main(int argc, char *argv[]) {
    FILE * fp = fopen("text.txt", "r");
    File F(fp);
    F.printLines(1);
    return 0;
}