如何在C++中解析定界符后的部分疑难解答?

最近刚开始学习C++。 我正在尝试以以下格式读取ics文件:

BEGIN:VEVENT
UID:2179:203860:1:002:1:person
DTSTAMP:20170921T080000Z
SUMMARY;LANGUAGE=en-ca:BIG CITY
LOCATION:CANADA
DTSTART;TZID=Eastern Standard Time:20170914T183000
DTEND;TZID=Eastern Standard Time:20170914T203000
RRULE:FREQ=WEEKLY;UNTIL=20171201T235959;BYDAY=TH
CLASS:PUBLIC
PRIORITY:5
TRANSP:OPAQUE
STATUS:CONFIRMED
SEQUENCE:0
END:VEVENT 

我所做的是读取每一行并调用一个字符串来找到特定的定界符,得到它后面的部分,并将其推到一个向量中。 以下是我读取文件的方法:

void SimpleCalendar::initialize(){
    int counter = 0;
    string getLine;
    ifstream readFile;
    readFile.open("cal.ics");

if(readFile.fail()){
    throw FileException("Error! Cannot open the file.");
}

while(!readFile.eof()){
    readFile >> getLine;
    size_t summ = getLine.find("SUMMARY;LANGUAGE=en-ca:");
    if (summ != string::npos){
        course.push_back(getLine.substr(summ+1));
        cout << course[counter] << endl;
        counter++;
    }
}

它应该输出的是: BIG CITY 相反,我得到了这个-> SUMMARY;LANGUAGE=en-ca:BIG