circular-dependency

问题 class CDB; class CDM { public: friend CDB& CDB::Add(const CDM&); CDM& Add(const CDB&); }; class CDB { public: CDB& Add(const CDM&); friend CDM& CDM::Add(const CDB&); }; This code gives me the error : error C2027: use of undefined type 'CDB'. How to resolve this. 回答1: No, you can't do that. There is no way to remove the cyclic dependency. You should be able to get by with making the class CDB a friend of CDM instead of wanting to making CDB::Add() a friend. class CDB; class CDM { public:

问题 My application is a Gradle Multi Module Project, consisting of multiple services with one service-common module. I´ve pulled all dependencies that all modules have in common out into the root build.gradle, and I also want to include the service-common module in all subprojects, which in theory works, but I´m getting a circular dependency issue because it is included in itself. apply plugin: 'java' group = 'com.myapplication' ext { set('springCloudVersion', "2.2.0.RELEASE") set(

问题 Why doesn't the following code compile and how can I fix it? The error I get is: Use of undeclared identifier 'Foo' although Foo is clearly declared and defined at the point where the error occurs (at the friend declaration in Bar ). foo.h : #ifndef FOO_H #define FOO_H #include "bar.h" // needed for friend declaration in FooChild class Foo { public: void Func(const Bar&) const; }; class FooChild : public Foo { friend void Bar::Func(FooChild*); }; #endif foo.cpp : #include "foo.h" void Foo:

问题 Why doesn't the following code compile and how can I fix it? The error I get is: Use of undeclared identifier 'Foo' although Foo is clearly declared and defined at the point where the error occurs (at the friend declaration in Bar ). foo.h : #ifndef FOO_H #define FOO_H #include "bar.h" // needed for friend declaration in FooChild class Foo { public: void Func(const Bar&) const; }; class FooChild : public Foo { friend void Bar::Func(FooChild*); }; #endif foo.cpp : #include "foo.h" void Foo:

问题 Assume the following package structure with code inline: main.py from a.b import c a/__init__.py a/b/__init__.py a/b/c.py from a.b import d a/b/d.py from a.b import c python2 main.py gives me an import error: Traceback (most recent call last): File "main.py", line 1, in <module> from a.b import c File "/home/runner/a/b/c.py", line 1, in <module> from a.b import d File "/home/runner/a/b/d.py", line 1, in <module> from a.b import c ImportError: cannot import name c However python3 main.py works

问题 Though the practice that I have been following could be inappropriate. Still looking for a fix to my problem here : I'm getting a StackOverflowError :: java.lang.StackOverflowError at com.my.package.pages.Selendroid.HomePage.<init>(HomePage.java:11) at com.my.package.pages.Selendroid.LoginPage.<init>(LoginPage.java:14) at com.my.package.pages.Selendroid.HomePage.<init>(HomePage.java:11) AppiumBasePage :: public class AppiumBasePage { protected AppiumDriver driver; HomePage :: public class

问题 I'm using a package called percent indicator https://pub.dev/packages/percent_indicator and I'm currently using its CircularPercentIndicator() I'm just wondering how to change the progress color when a certain percentage met? For example: I have a starting progress color of green at 0% when reaching 60% progress color should change to orange and when reaching 80% color should be red. here's what I got at the moment: import 'package:flutter/material.dart'; import 'package:percent_indicator

问题 I'm using a package called percent indicator https://pub.dev/packages/percent_indicator and I'm currently using its CircularPercentIndicator() I'm just wondering how to change the progress color when a certain percentage met? For example: I have a starting progress color of green at 0% when reaching 60% progress color should change to orange and when reaching 80% color should be red. here's what I got at the moment: import 'package:flutter/material.dart'; import 'package:percent_indicator

问题 I am faced with a problem that gives me this error: A circular reference has been detected when serializing the object of class "App\Entity\User" (configured limit: 1) I have an Enterprise entity that has mission orders, vehicles, and users. An orders entity that has a relationship with a User, Company, and Vehicle. And a User entity that has a relationship with orders and company. So I have this: Entreprise.php class Entreprise { /** * @ORM\Id() * @ORM\GeneratedValue() * @ORM\Column(type=

来源： https://stackoverflow.com/questions/61978534/how-to-implement-chained-models-with-loopback-4-without-getting-a-circular-depen