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我认为这与 C++ 链接器错误有关，而不是与节俭有关。我对 thrift 文件进行了更改并重新生成了 cpp 和 java 类。进行此更改后，我开始在 cpp 中收到链接器错误。这是错误

未定义的符号：

"com::XXXX::thrift::employee::SavingsInfo::operator<(com::XXXX::thrift::employee::SavingsInfo const&) const", referenced from: std::less::operator()(com::XXXX::thrift::employee::SavingsInfo const&, com::XXXX::thrift::employee::SavingsInfo const&) constin employee_types.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [ThriftCPPSamples] Error 1

我在 thrift 文件中添加了 SavingsInfo 类型，这是我所做的更改。我将文档中提到的所有选项都提供给 g++。我给了-I/usr/local/include/thrift, -I/path-to-boost, -L/path-to-boost-lib, -lthrift. 但是在更改之后，我开始收到上述链接器错误。我无法理解这其中的原因。该错误指向thrift 生成的某些内容。错误的原因可能是什么？

这个错误是关于“operator <”的，所以我只发布与之相关的代码。完整的代码可从最后提供的两个链接中获得。

员工类型.h

class SavingsInfo {
public:
    std::string name;
    double amount;
    bool operator == (const SavingsInfo & rhs) const { /*...*/ }
    bool operator != (const SavingsInfo &rhs) const { return !(*this == rhs); }
    bool operator < (const SavingsInfo & ) const;
    uint32_t read(::apache::thrift::protocol::TProtocol* iprot);
    uint32_t write(::apache::thrift::protocol::TProtocol* oprot) const;
};

class EmployeeInfo {
public:
    int32_t id;
    std::string name;
    double salary;
    bool contract;
    std::set<std::string>  dependents;
    std::set<SavingsInfo>  savings;
    bool operator == (const EmployeeInfo & rhs) const { /*...*/ }
    bool operator != (const EmployeeInfo &rhs) const { return !(*this == rhs); }
    bool operator < (const EmployeeInfo & ) const;
    uint32_t read(::apache::thrift::protocol::TProtocol* iprot);
    uint32_t write(::apache::thrift::protocol::TProtocol* oprot) const;
};

员工类型.cpp

uint32_t EmployeeInfo::read(::apache::thrift::protocol::TProtocol* iprot) {
    uint32_t xfer = 0;
    std::string fname;
    ::apache::thrift::protocol::TType ftype;
    int16_t fid;
    xfer += iprot->readStructBegin(fname);
    using ::apache::thrift::protocol::TProtocolException;
    while (true)
    {
        xfer += iprot->readFieldBegin(fname, ftype, fid);
        if (ftype == ::apache::thrift::protocol::T_STOP) {
            break;
        }
        switch (fid)
        {
            // removed the case statements which deal with reading other fields
        case 6:
            if (ftype == ::apache::thrift::protocol::T_SET) {
                {
                    this->savings.clear();
                    uint32_t _size6;
                    ::apache::thrift::protocol::TType _etype9;
                    iprot->readSetBegin(_etype9, _size6);
                    uint32_t _i10;
                    for (_i10 = 0; _i10 < _size6; ++_i10)
                    {
                        SavingsInfo _elem11;
                        xfer += _elem11.read(iprot);
                        this->savings.insert(_elem11);
                    }
                    iprot->readSetEnd();
                }
                this->__isset.savings = true;
            } else {
                xfer += iprot->skip(ftype);
            }
            break;
        default:
            xfer += iprot->skip(ftype);
            break;
        }
        xfer += iprot->readFieldEnd();
    }
    xfer += iprot->readStructEnd();
    return xfer;
}

uint32_t EmployeeInfo::write(::apache::thrift::protocol::TProtocol* oprot) const {
    uint32_t xfer = 0;
    // removed the write statements for other fields
    xfer += oprot->writeStructBegin("EmployeeInfo");
    xfer += oprot->writeFieldBegin("savings", ::apache::thrift::protocol::T_SET, 6);
    {
        xfer += oprot->writeSetBegin(::apache::thrift::protocol::T_STRUCT,   
            this->savings.size());
        std::set<SavingsInfo> ::const_iterator _iter13;
        for (_iter13 = this->savings.begin(); _iter13 != this->savings.end(); ++_iter13)
        {
            xfer += (*_iter13).write(oprot);
        }
        xfer += oprot->writeSetEnd();
    }
    xfer += oprot->writeFieldEnd();
    xfer += oprot->writeFieldStop();
    xfer += oprot->writeStructEnd();
    return xfer;
}

我尝试过的其他几件事：

  1. 如果我使用 SavingsInfo，而不是 set<SavingsInfo>，它​​可以正常工作。
  2. 在employee_types.h 中评论了“operator <”，因为我不知道它在哪里被使用。我收到以下构建错误

Building file: ../src/employee_types.cpp Invoking: GCC C++ Compiler g++ -I/usr/local/include/thrift -I/Users/raghava/Software/Boost_C++_Library/boost_1_43_0 -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/employee_types.d" -MT"src/employee_types.d" -o"src/employee_types.o" "../src/employee_types.cpp" /usr/include/c++/4.2.1/bits/stl_function.h: In member function 'bool std::less<_Tp>::operator()(const _Tp&, const _Tp&) const [with _Tp = com::xxxx::thrift::employee::SavingsInfo]': /usr/include/c++/4.2.1/bits/stl_tree.h:982: instantiated from 'std::pair::iterator, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique(const _Val&) [with _Key = com::xxxx::thrift::employee::SavingsInfo, _Val = com::xxxx::thrift::employee::SavingsInfo, _KeyOfValue = std::_Identity, _Compare = std::less, _Alloc = std::allocator]' /usr/include/c++/4.2.1/bits/stl_set.h:307: instantiated from 'std::pair, _Compare, typename _Alloc::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(const _Key&) [with _Key = com::xxxx::thrift::employee::SavingsInfo, _Compare = std::less, _Alloc = std::allocator]' ../src/employee_types.cpp:163: instantiated from here /usr/include/c++/4.2.1/bits/stl_function.h:227: error: no match for 'operator<' in '__x < __y' make: *** [src/employee_types.o] Error 1

这两个文件的完整源代码在下面的链接中给出。另一个链接在评论中（在我获得 10 分的声誉之前我不能发布它）。

employee_types.cpp -- http://pastebin.com/7dLtstCK
employee_types.h -- http://pastebin.com/JGzE8V6J

谢谢你。

问候，拉格哈瓦。

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