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  • C++ dynamic type construction and detection

    - by KneLL
    There was an interesting problem in C++, but it concerns more likely architecture. There are many (10, 20, 40, etc) classes that describe some characteristics (mix-in classes), for exmaple: struct Base { virtual ~Base() {} }; struct A : virtual public Base { int size; }; struct B : virtual public Base { float x, y; }; struct C : virtual public Base { bool some_bool_state; }; struct D : virtual public Base { string str; } // .... Primary module declares and exports a function (for simplicity just function declarations without classes): // .h file void operate(Base *pBase); // .cpp file void operate(Base *pBase) { // .... } Any other module can has a code like this: #include "mixins.h" #include "primary.h" class obj1_t : public A, public C, public D {}; class obj2_t : public B, public D {}; // ... void Pass() { obj1_t obj1; obj2_t obj2; operate(&obj1); operate(&obj2); } The question is how to know what the real type of given object in operate() without dynamic_cast and any type information in classes (constants, etc)? Function operate() is used with big array of objects in small time periods and dynamic_cast is too slow for it. And I don't want to include constants (enum obj_type { ... }) because this is not OOP-way. // module operate.cpp void some_operate(Base *pBase) { processA(pBase); processB(pBase); } void processA(A *pA) { } void processB(B *pB) { } I cannot directly pass a pBase to these functions. And it's impossible to have all possible combinations of classes, because I can add new classes just by including new .h files. As one of solutions that comed to mind, in editor application I can use a composite container: struct CompositeObject { vector<Base *pBase> parts; }; But editor does not need a time optimization and can use dynamic_cast for parts to determine the exact type. In operate() I cannot use this solution. So, is it possible to not use a dynamic_cast and type information to solve this problem? Or maybe I should use another architecture?

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  • SQL Server Text type v.s. varchar data type

    - by George2
    Hello everyone, I have variable length character and want to store in SQL Server (2005) database. I want to learn some best practices about how to choose TEXT SQL type or choose VARCHAR SQL type, pros and cons in performance/footprint/function. thanks in advance, George

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  • valid attributes sequence of input type tag

    - by I Like PHP
    hello, I know it's very basic question and hope not so important, but i want to know the answer, please don't suggest only refer links. we all daily face <input> type tag and their attributes(type, class, id, value, name, size, maxlength, tabindex etc..), i just want to know that is there any sequence list of attributes in tag or we can use any sequence? is there any sequence then what it is?

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  • Using type passed as a template in C++

    - by MeDiCS
    Is it possible to actually use the type passed as a template for control flow? I'd like to write a function that uses templates, which in turn calls another function based on the type passed: template <class T> void test_function (T var) { //Do stuff if (T == char) { bar (var); } else { foo (var); } //Do even more stuff } If not, I'll have to fallback to enums...

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  • C++ function dynamic data type definition

    - by user330352
    Hi all, in C++, when you define a function which takes one argument, you have to define the data type of that variable: void makeProccess(int request) However, I want to implement a function which takes different data types rather taking statically defined integer type. void makeProccess(anyType request) How can I design a proccess like this, any idea? Thanks.

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  • storing characters in char data type C language

    - by iSight
    Hi, I can store string of few length in char data type. But when it exceeds its capacity what can be the alternative way to store string. I am using char data type. void setString(char* inPoints) { if (strcmp(mPoints, inPoints)!= ZERO) { if (mPoints) { free(mPoints); } mPoints = (char*)malloc((strlen(inPoints) + 1) * sizeof(char)); strcpy(mPoints, inPoints); } }

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  • Restrict a generic type

    - by Water Cooler v2
    I want to restrict the generic type parameter to: 1) either that of a certain user defined reference type; OR 2) any of the primitive types in the CLR; How do I say something to the effect of: interface IDataManager<T>: IDataManager where T: IDataObject, T: ValueType

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  • Swap partition not recognized (The disk drive with UUID=... is not ready yet or not present)

    - by ladaghini
    I think I had an encrypted swap partition, because I chose to encrypt my home directory during the installation. I believe that's what the line with /dev/mapper/cryptswap1 ... in my /etc/fstab is all about. I did something to bork my swap because on the next boot, I got a message (paraphrased): The disk drive for /dev/mapper/cryptswap1 is not ready yet or not present. Wait to continue. Press S to skip or M to manually recover. (As a side note, pressing S or M seemed to do nothing different from just waiting.) Here's what I've tried: This tutorial on how to fix the swap partition not mounting. However, in the above, the mkswap command fails because the device is busy. So I booted from a live USB, ran GParted to reformat the swap partition (which showed up as an unknown fs type), and chrooted into the broken system to try that tutorial again. I also adjusted /etc/initramfs-tools/conf.d/resume and /etc/fstab to reflect the new UUID generated from formatting the partition as a swap. That still didn't work; instead of /dev/mapper/cryptswap1 not present, "The disk drive with UUID=[swap partition's UUID] is not ready yet or not present..." So I decided to start afresh as though I never had created a swap partition in the first place. From the Live USB, I deleted the swap partition altogether (which, again showed up in GParted as an unknown fs type), removed the swap and cryptswap entries in /etc/fstab as well as removed /etc/initramfs-tools/conf.d/resume and /etc/crypttab. At this point the main system shouldn't be considered broken because there is no swap partition and no instructions to mount one, right? I didn't get any errors during startup. I followed the same instructions to create and encrypt the swap partition, starting with creating a partition for the swap, though I think fdisk said a reboot was necessary to see changes. I was confident the 3rd process above would work, but the problem yet persists. Some relevant info (/dev/sda8 is the swap partition): /etc/fstab file: # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc nodev,noexec,nosuid 0 0 # / was on /dev/sda6 during installation UUID=4c11e82c-5fe9-49d5-92d9-cdaa6865c991 / ext4 errors=remount-ro 0 1 # /boot was on /dev/sda5 during installation UUID=4031413e-e89f-49a9-b54c-e887286bb15e /boot ext4 defaults 0 2 # /home was on /dev/sda7 during installation UUID=d5bbfc6f-482a-464e-9f26-fd213230ae84 /home ext4 defaults 0 2 # swap was on /dev/sda8 during installation UUID=5da2c720-8787-4332-9317-7d96cf1e9b80 none swap sw 0 0 /dev/mapper/cryptswap1 none swap sw 0 0 output of sudo mount: /dev/sda6 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) /dev/sda5 on /boot type ext4 (rw) /dev/sda7 on /home type ext4 (rw) /home/undisclosed/.Private on /home/undisclosed type ecryptfs (ecryptfs_check_dev_ruid,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs,ecryptfs_sig=cbae1771abd34009,ecryptfs_fnek_sig=7cefe2f59aab8e58) gvfs-fuse-daemon on /home/undisclosed/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=undisclosed) output of sudo blkid (note that /dev/sda8 is missing): /dev/sda1: LABEL="SYSTEM" UUID="960490E80490CC9D" TYPE="ntfs" /dev/sda2: UUID="D4043140043126C0" TYPE="ntfs" /dev/sda3: LABEL="Shared" UUID="80F613E1F613D5EE" TYPE="ntfs" /dev/sda5: UUID="4031413e-e89f-49a9-b54c-e887286bb15e" TYPE="ext4" /dev/sda6: UUID="4c11e82c-5fe9-49d5-92d9-cdaa6865c991" TYPE="ext4" /dev/sda7: UUID="d5bbfc6f-482a-464e-9f26-fd213230ae84" TYPE="ext4" /dev/mapper/cryptswap1: UUID="41fa147a-3e2c-4e61-b29b-3f240fffbba0" TYPE="swap" output of sudo fdisk -l: Disk /dev/mapper/cryptswap1 doesn't contain a valid partition table Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xdec3fed2 Device Boot Start End Blocks Id System /dev/sda1 * 2048 409599 203776 7 HPFS/NTFS/exFAT /dev/sda2 409600 210135039 104862720 7 HPFS/NTFS/exFAT /dev/sda3 210135040 415422463 102643712 7 HPFS/NTFS/exFAT /dev/sda4 415424510 625141759 104858625 5 Extended /dev/sda5 415424512 415922175 248832 83 Linux /dev/sda6 415924224 515921919 49998848 83 Linux /dev/sda7 515923968 621389823 52732928 83 Linux /dev/sda8 621391872 625141759 1874944 82 Linux swap / Solaris Disk /dev/mapper/cryptswap1: 1919 MB, 1919942656 bytes 255 heads, 63 sectors/track, 233 cylinders, total 3749888 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xaf5321b5 /etc/initramfs-tools/conf.d/resume file: RESUME=UUID=5da2c720-8787-4332-9317-7d96cf1e9b80 /etc/crypttab file: cryptswap1 /dev/sda8 /dev/urandom swap,cipher=aes-cbc-essiv:sha256 output of sudo swapon -as: Filename Type Size Used Priority /dev/mapper/cryptswap1 partition 1874940 0 -1 output of sudo free -m: total used free shared buffers cached Mem: 1476 1296 179 0 35 671 -/+ buffers/cache: 590 886 Swap: 1830 0 1830 So, how can this be fixed?

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  • Is there such thing as a "theory of system integration"?

    - by Jeff
    There is a plethora of different programs, servers, and in general technologies in use in organizations today. We, programmers, have lots of different tools at our disposal to help solve various different data, and communication challenges in an organization. Does anyone know if anyone has done an serious thinking about how systems are integrated? Let me give an example: Hypothetically, let's say I own a company that makes specialized suits a'la Iron Man. In the area of production, I have CAD tools, machining tools, payroll, project management, and asset management tools to name a few. I also have nice design space, where designers show off their designs on big displays, some touch, some traditional. Oh, and I also have one of these new fangled LEED Platinum buildings and it has number of different computer controlled systems, like smart window shutters that close when people are in the room, a HVAC system that adjusts depending on the number of people in the building, etc. What I want to know is if anyone has done any scientific work on trying to figure out how to hook all these pieces together, so that say my access control system is hooked to my payroll system, and my phone system allowing my never to swipe a time card, and to have my phone follow me throughout the building. This problem is also more than a technology challenge. Every technology implementation enables certain human behaviours, so the human must also be considered as a part of the system. Has anyone done any work in how effectively weave these components together? FYI: I am not trying to build a system. I want to know if anyone has thoroughly studied the process of doing a large integration project, how they develop their requirements, how they studied the human behaviors, etc.

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  • post xml to Spring REST server returns Unsupported Media Type

    - by Mayra
    I'm trying to create a simple spring based webservice that supports a "post" with xml content. In spring, I define an AnnotationMethodHandler: <bean id="inboundMessageAdapter" class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> <property name="messageConverters"> <util:list> <bean class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter"> <property name="marshaller" ref="xmlMarshaller"/> <property name="unmarshaller" ref="xmlMarshaller"/> </bean> </util:list> </property> </bean> And a jaxb based xml marshaller: <bean id="xmlMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller"> <property name="contextPaths"> <array> <value>com.company.schema</value> </array> </property> <property name="schemas"> <array> <value>classpath:core.xsd</value> </array> </property> </bean> My controller is annotated as follows, where "Resource" is a class autogenerated by jaxb: @RequestMapping(method = POST, value = "/resource") public Resource createResource(@RequestBody Resource resource) { // do work } The result of a webservice call is always "HTTP/1.1 415 Unsupported Media Type". Here is an example service call: HttpPost post = new HttpPost(uri); post.addHeader("Accept", "application/xml"); post.addHeader("Content-Type", "application/xml"); StringEntity entity = new StringEntity(request, "UTF-8"); entity.setContentType("application/xml"); post.setEntity(entity); It seems to me that I am setting the correct media type everywhere possible. Anyone have an ideas?

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  • InvalidCastException for two Objects of the same type

    - by LLEA
    hi, I have this weird problem that I cannot handle myself. A class in the model of my mvp-project designed as singleton causes an InvalidCastException. The source of error is found in this code line where the deserialised object is assigned to the instance variable of the class: engineObject = (ENGINE)xSerializer.Deserialize(str); It occurs whenever I try to add one of my UserControls to a Form or to a different UC. All of my UCs have a special presenter that access the above mentioned instance variable of the singleton class. This is what I get when trying to add a UC somewhere: 'System.TypeInitializationException: The type initializer for 'MVP.Model.EngineData' threw an exception. ---- System.InvalidCastException: [A]Engine cannot be cast to [B]Engine. Type A originates from 'MVP.Model, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'LoadNeither' at location '[...]\AppData\Roaming\Microsoft\VisualStudio\9.0\ProjectAssemblies\uankw1hh01\MVP.Model.dll'. Type B originates from 'MVP.Model, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'LoadNeither' at location '[...]\AppData\Roaming\Microsoft\VisualStudio\9.0\ProjectAssemblies\u_hge2de01\MVP.Model.dll'... So I somehow have two assemblies and they are not accessed from my project folder, but from a VS temp folder? I googled a lot and only found this: IronPython Exception: [A]Person cannot be cast to [B]Person. There is a solution offered, but first it concerns IronPhyton and second I don't know where to use it within my project? It would be just great, if u could help me out here :-) thx

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  • javascript removeChild(this) from input[type="submit"] onclick breaks future use of form.submit() un

    - by maximumduncan
    I have come across some strange behaviour, and I'm assuming a bug in firefox, when removing a input submit element from the DOM from within the click event. The following code reproduces the issue: <form name="test_form"> <input type="submit" value="remove me" onclick="this.parentNode.removeChild(this);" /> <input type="submit" value="submit normally" /> <input type="button" value="submit via js" onclick="document.test_form.submit();" /> </form> To reproduce: Click "remove me" Click "submit via js". Note that the form does not get submitted, this is the problem. Click "submit normally". Note that the form still gets submitted normally. It appears that, under Firefox, if you remove a submit button from within the click event it puts the form in an invalid state so that any future calls to form.submit() are simply ignored. But it is a javascript-specific issue as normal submit buttons within this form still function fine. To be honest, this is such a simple example of this issue that I was expecting the internet to be awash with other people exeriencing it, but so far searching has yealded nothing useful. Has anyone else experienced this and if so, did you get to the bottom of it? Many thanks

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  • Exporting non-public type through public API

    - by feelgood
    What if I have few factory methods returning non-public type and pairing set of methods which gives variables of this non-public type? This results with titled warning message in NetBeans. In result public API will contain only two pairing sets of methods. The reason is to make my type hierarchy sealed (like seald classes in Scala) and allow users only instantiate these types through factory methods. So we get DSL in some sense. For example, Schedule class represented by calendar fields' contraints. There are some types of contraints - Range, Singleton, List, FullSet - with NumberSet interface as a root. We don't want to expose these types and how Schedule interact with them. We just want the specification from the user. So we make NumberSet package-private. In class Schedule we create few factory-methods for constraints: NumberSet singleton(int value); NumberSet range(int form, int to); NumberSet list(NumberSet ... components); and some methods for creating Schedule object: Schedule everyHour(NumberSet minutes); Schedule everyDay(NumberSet minutes, NumberSet hours); User can only use them in the manner: Schedule s = Schedule.everyDay( singleton(0), list(range(10-15), singleton(8)) ); Is it bad idea?

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  • XMLBeans - xsi:type stripped using Axis2 and Tomcat?

    - by Matthew Gamble
    I’m new to XMLBeans and have been trying to use it to create an XML document as part of an axis2 web service. When I run my code as a standard Java application or as a standard servlet, the XML is correctly generated: <?xml version="1.0" encoding="UTF-8"?> <c:BroadsoftDocument protocol="OCI" xmlns:c="C"> <sessionId>000000001</sessionId> <command xsi:type="AuthenticationRequest" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <userId>admin</userId></command> </c:BroadsoftDocument> However, when the exact same code is run under Axis2 & Tomcat in a servlet I get: <?xml version="1.0" encoding="UTF-8"?> <c:BroadsoftDocument protocol="OCI" xmlns:c="C"> <sessionId>000000001</sessionId> <command> <userId>admin</userId></command> </c:BroadsoftDocument> This of course isn’t valid – the xsi:type of the “command” element is stripped when the code is run under Tomcat. Does anyone have any suggestions of what I could be doing wrong that would cause this type of issue only when running under Axis2? At first I thought it was a Tomcat issue, but after creating a generic servlet and running the exact same code I don't have any issues. I've tried playing with the XMLOptions for XMLBeans, but couldn't seem to resolve the problem. The options I'm currently using are: xmlOptions = new XmlOptions(); xmlOptions.setCharacterEncoding("UTF-8"); xmlOptions.setUseDefaultNamespace(); xmlOptions.setSaveAggressiveNamespaces(); xmlOptions.setSavePrettyPrint();

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  • Facebook app submit action type

    - by Axel
    I've been reading about this on StackOverflow and facebook doc, yet I dont seem to be able to submit my action type. I have the following code from the FB doc <script type="text/javascript"> console.log("Function begins"); function postForm() { console.log(FB); FB.api( '/me/concoursvelirium:form', 'post', { recipe: 'http://concours.gestev.com/fbvel2012/form.php' }, function(response) { console.log("Stay"); if (!response || response.error) { console.log("error: " + response); } else { console.log('Cook was successful! Action ID: ' + response.id); } }); } </script> I have added my values from FB autogenerated values: <head prefix="og: http://ogp.me/ns# fb: http://ogp.me/ns/fb# concoursvelirium: http://ogp.me/ns/fb/concoursvelirium#"> <meta property="fb:app_id" content="194081877384051" /> <meta property="og:type" content="concoursvelirium:form" /> <meta property="og:url" content="Put your own URL to the object here" /> <meta property="og:title" content="Sample Form" /> <meta property="og:image" content="https://s-static.ak.fbcdn.net/images/devsite/attachment_blank.png" /> And yet I see no output in the console past the console.log(FB); I have no idea what I'm doing wrong. I'm also getting the Unsafe JavaScript attempt to access frame with URL error, but I have read here that I should just ignore it. Ty, Axel

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  • boost lambda::bind return type selection

    - by psaghelyi
    I would like to call a member through lambda::bind. Unfortunately I have got to members with the same name but different return type. Is there a way to help the lambda::bind to deduce the right return type for a member function call? #include <vector> #include <iostream> #include <algorithm> #include <boost/bind.hpp> #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> using namespace std; using namespace boost; struct A { A (const string & name) : m_name(name) {} string & name () { return m_name; } const string & name () const { return m_name; } string m_name; }; vector<A> av; int main () { av.push_back (A ("some name")); // compiles fine find_if(av.begin(), av.end(), bind<const string &>(&A::name, _1) == "some name"); // error: call of overloaded 'bind(<unresolved overloaded function type>, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >&)' is ambiguous find_if(av.begin(), av.end(), lambda::bind(&A::name, lambda::_1) == "some name"); return 0; }

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  • Instantiate type variable in Haskell

    - by danportin
    EDIT: Solved. I was unware that enabling a language extension in the source file did not enable the language extension in GHCi. The solution was to :set FlexibleContexts in GHCi. I recently discovered that type declarations in classes and instances in Haskell are Horn clauses. So I encoded the arithmetic operations from The Art of Prolog, Chapter 3, into Haskell. For instance: fac(0,s(0)). fac(s(N),F) :- fac(N,X), mult(s(N),X,F). class Fac x y | x -> y instance Fac Z (S Z) instance (Fac n x, Mult (S n) x f) => Fac (S n) f pow(s(X),0,0) :- nat(X). pow(0,s(X),s(0)) :- nat(X). pow(s(N),X,Y) :- pow(N,X,Z), mult(Z,X,Y). class Pow x y z | x y -> z instance (N n) => Pow (S n) Z Z instance (N n) => Pow Z (S n) (S Z) instance (Pow n x z, Mult z x y) => Pow (S n) x y In Prolog, values are insantiated for (logic) variable in a proof. However, I don't understand how to instantiate type variables in Haskell. That is, I don't understand what the Haskell equivalent of a Prolog query ?-f(X1,X2,...,Xn) is. I assume that :t undefined :: (f x1 x2 ... xn) => xi would cause Haskell to instantiate xi, but this gives a Non type-variable argument in the constraint error, even with FlexibleContexts enabled.

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  • XML Schema and element with type string

    - by svick
    I'm trying to create an XML Schema and I'm stuck. It seems I can't define an element with string content. What am I doing wrong? Schema: <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://ponderka.wz.cz/MusicLibrary0" targetNamespace="http://ponderka.wz.cz/MusicLibrary0"> <xs:element name="music-library"> <xs:complexType> <xs:sequence> <xs:element name="artist" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:element> </xs:schema> Document: <?xml version="1.0"?> <music-library xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://ponderka.wz.cz/MusicLibrary0 data0.xsd" xmlns="http://ponderka.wz.cz/MusicLibrary0"> <artist>a</artist> </music-library> The validator says: Element <artist> is not allowed under element <music-library>. Reason: The following elements are expected at this location (see below) <artist> Error location: music-library / artist Details cvc-model-group: Element <artist> unexpected by type '{anonymous}' of element <music-library>. cvc-elt.5.2.1: The element <music-library> is not valid with respect to the actual type definition '{anonymous}'.

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