How to add custom data types to the queue?-CodePudding

Add the regular data types, is simple:

 
STD: : queue ReqQueue; 
ReqQueue. Push (1);

But when I try to insert the data types defined themselves when I was puzzled:

Such as my object:

 
The class ReqMsg 
{
Public: 
ReqMsg (string & amp; M, string & amp; P, int ver, int id) 
{
Method=m; 
Params=p; 
_ver=ver; 
_id=id; 
} 
~ ReqMsg (); 
String method;//the method name 
String params.//parameter 
Int _ver;//version 
Int _id.//id 
}

I can't directly add it like this:

 
STD: : queue ReqQueue; 
ReqQueue. Push (new ReqMsg);

CodePudding user response:

STD: : queue

A=new ReqMsg ReqMsg * ();
ReqQueue. Push (a);

ReqQueue deleted elements, remember to delete;

CodePudding user response:

STD: : queue ReqQueue;
ReqQueue. Push (ReqMsg ());

CodePudding user response:

refer to the second floor truth is right or wrong response:

STD: : queue ReqQueue;
ReqQueue. Push (ReqMsg ());

you can't

CodePudding user response:

reference bdview reply: 3/f

Quote: refer to the second floor truth is right or wrong response:
STD: : queue ReqQueue;
ReqQueue. Push (ReqMsg ());

you no

Your class does not have a default constructor.

CodePudding user response:

Since want to reference your class constructor parameters, the best transfer const string&

 # include & lt; Iostream> 
#include  
#include  
using namespace std; 
The class ReqMsg 
{
Public: 
ReqMsg (const string& M, const string& P, int ver, int id) 
{
Method=m; 
Params=p; 
_ver=ver; 
_id=id; 
} 
~ ReqMsg () {}; 
String method;//the method name 
String params.//parameter 
Int _ver;//version 
Int _id.//id 
}; 
Int main () {
Queue q; 
Q.p ush (ReqMsg (string (" ABC "), string (edf), 1, 4)); 
return 1; 
}

CodePudding user response:

refer to fifth floor truth is right or wrong response:

you e]

you really work this way!

Have a question want to ask you

Why is my constructor is the following:

 ReqMsg (string & amp; M, string & amp; P, int ver, int id) 
{
Method=m; 
Params=p; 
_ver=ver; 
_id=id; 
}

Such use
MsgQueue. Push (ReqMsg (" name1 ", "param1", 2, 1));
Why error:
severity code shows the project file line prohibits display status
Error C2440 "& lt; The function - style - cast>" : can't transfer from ", initializer list "to" ReqMsg easyTest "e: \ svndir 15 - learning c + + \ \ c + + exercise \ easyTest \ easyTest \ easyTest CPP 185

To this also not line:
MsgQueue. Push (ReqMsg (string (" name1 "), string (" param1 "), 2, 1));

The constructor to:

 ReqMsg (const string& M, const string& P, int ver, int id) 
{
Method=m; 
Params=p; 
_ver=ver; 
_id=id; 
}

Then relief can be like this:

MsgQueue. Push (ReqMsg (" name1 ", "param1", 2, 1));