c++ - proto c++ 实现 - "marked ‘override’，但不会覆盖“错误

Question

// api_internal.proto
service InvoiceTemplateMatcher {
   rpc Process(InvoiceFilePath) returns (UploadStatus) {}
}

message InvoiceFilePath {
   string invoice_id = 1;
   string file_path = 2;
}

// template_matcher/src/main.cc
class OrkaEngineInvoiceTemplateMatcherImpl final : public InvoiceTemplateMatcher::Service {
private:
    Status Process(
        ServerContext* context,
        orka_engine_internal::InvoiceFilePath* invoicefp,
        orka_engine_internal::UploadStatus* response) override {
    // do stuff
    }
};

类 InvoiceTemplateMatcher::Service 是在编译期间从那个 .proto 文件生成的。

当我尝试编译时，出现错误

‘grpc::Status OrkaEngineInvoiceTemplateMatcherImpl::Process(grpc::ServerContext*, orka_engine_internal::InvoiceFilePath*, orka_engine_internal::UploadStatus*)’ marked ‘override’, but does not override
     Status Process(ServerContext* context, orka_engine_internal::InvoiceFilePath* invoicefp, orka_engine_internal::UploadStatus* response) override {

据我所知，我的代码编写方式与 Route Guide example 中的相同.我错过了什么？

Answer 1

当函数未在基类中标记为 virtual 时，编译器会发出此类错误。

考虑以下最小示例:

class Base{
    void Foo() {}
};

class Derived : Base{
    void Foo() override {}
};

编译器发出错误:

error: 'void Derived::Foo()' marked 'override', but does not override
     void Foo() override {}

参见 Demo

override说明符指定 virtual 函数覆盖另一个 virtual 函数。