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  • Sort list using stl sort function

    - by Vlad
    I'm trying to sort a list (part of a class) in descending containg items of a struct but it doesn't compile(error: no match for 'operator-' in '__last - __first'): sort(Result.poly.begin(), Result.poly.end(), SortDescending()); And here's SortDescending: struct SortDescending { bool operator()(const term& t1, const term& t2) { return t2.pow < t1.pow; } }; Can anyone tell me what's wrong? Thanks!

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  • DotNetOpenAuth: Mock ClaimsResponse

    - by Pickels
    Hello, I was wondering how I can mock the ClaimseReponse class in DotNetOpenAuth? This is the class(remove a few properties): [Serializable] public sealed class ClaimsResponse : ExtensionBase, IClientScriptExtensionResponse, IExtensionMessage, IMessageWithEvents, IMessage { public static bool operator !=(ClaimsResponse one, ClaimsResponse other); public static bool operator ==(ClaimsResponse one, ClaimsResponse other); [MessagePart("email")] public string Email { get; set; } [MessagePart("fullname")] public string FullName { get; set; } public override bool Equals(object obj); public override int GetHashCode(); } This is what I tried: ClaimsResponse MockCR = new ClaimsResponse(); MockCR.Email = "[email protected]"; MockCR.FullName = "Mister T"; I get the following error: '...ClaimsResponse(string)' is inaccessible due to its protection level. Kind regards, Pickels

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  • C++ Why is the converter constructor implicitly called?

    - by ShaChris23
    Why is the Child class's converter constructor called in the code below? I mean, it automatically converts Base to Child via the Child converter constructor. The code below compiles, but shouldn't it not compile since I haven't provided bool Child::operator!=(Base const&)? class Base { }; class Child : public Base { public: Child() {} Child(Base const& base_) : Base(base_) { std::cout <<"should never called!"; } bool operator!=(Child const&) { return true; } }; void main() { Base base; Child child; if(child != base) std::cout << "not equal"; else std::cout << "equal"; }

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  • How to read verbose VC++ linker output

    - by Assaf Lavie
    Trying to debug some linker errors, I turned on /VERBOSE and I'm trying to make sense of the output. It occurs to me that I really don't know how to read it. For example: 1>Compiling version info 1>Linking... 1>Starting pass 1 1>Processed /DEFAULTLIB:mfc80.lib 1>Processed /DEFAULTLIB:mfcs80.lib 1>Processed /DEFAULTLIB:msvcrt.lib 1>Processed /DEFAULTLIB:kernel32.lib 1>Processed /DEFAULTLIB:user32.lib .... 1>Processed /DEFAULTLIB:libgslcblasMD.lib 1>Searching libraries 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) 1>Processed /DEFAULTLIB:CGAL-vc80-mt.lib 1>Processed /DEFAULTLIB:boost_thread-vc80-mt-1_33_1.lib What's going on here? I think I understand this bit: 1>Processed /DEFAULTLIB:libgslcblasMD.lib 1>Searching libraries 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) It's trying to find the implementation of the above operator, which is used somewhere in FocusDlg.cpp, and it finds it in geometry.lib. But what does 1>Processed /DEFAULTLIB:libgslcblasMD.lib mean? What determines the order of symbol resolution? Why is it loading this particular symbol while processing libgslcblasMD.lib which is a 3rd party library? Or am I reading it wrong? It seems that the linker is going through the symbols referenced in the project's various object files, but I have no idea in what order. It then searches the static libraries the project uses - by project reference, explicit import and automatic default library imports; but it does so in an order that, again, seems arbitrary to me. When it finds a symbol, for example in geometry.lib, it then continues to find a bunch of other symbols from the same lib: 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) 1>Processed /DEFAULTLIB:CGAL-vc80-mt.lib 1>Processed /DEFAULTLIB:boost_thread-vc80-mt-1_33_1.lib 1> Found "public: __thiscall VisionMap::Geometry::Box2DInt::Box2DInt(int,int,int,int)" (??0Box2DInt@Geometry@VisionMap@@QAE@HHHH@Z) 1> Referenced in FocusDlg.obj 1> Referenced in ImageView.obj 1> Referenced in geometry.lib(Box2d.obj) 1> Loaded geometry.lib(Box2DInt.obj) 1> Found "public: virtual __thiscall VisionMap::Geometry::Point3d::~Point3d(void)" (??1Point3d@Geometry@VisionMap@@UAE@XZ) 1> Referenced in GPSFrm.obj 1> Referenced in MainFrm.obj 1> Loaded geometry.lib(Point3d.obj) 1> Found "void __cdecl VisionMap::Geometry::serialize<class boost::archive::binary_oarchive>(class boost::archive::binary_oarchive &,class VisionMap::Geometry::Point3d &,unsigned int)" (??$serialize@Vbinary_oarchive@archive@boost@@@Geometry@VisionMap@@YAXAAVbinary_oarchive@archive@boost@@AAVPoint3d@01@I@Z) 1> Referenced in GPSFrm.obj 1> Referenced in MainFrm.obj 1> Loaded geometry.lib(GeometrySerializationImpl.obj) But then, for some reason, it goes on to find symbols that are defined in other libs, and returns to geometry later on (a bunch of times). So clearly it's not doing "look in geometry and load every symbol that's references in the project, and then continue to other libraries". But it's not clear to me what is the order of symbol lookup. And what's the deal with all those libraries being processed at the beginning of the linker's work, but not finding any symbols to load from them? Does this project really not use anything from msvcrt.lib, kernel32.lib? Seems unlikely. So basically I'm looking to decipher the underlying order in the linker's operation.

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  • Boost bind function

    - by Gokul
    Hi, I have a abstract base class A and a set of 10 derived classes. The infix operator is overloaded in all of the derived classes class A{ void printNode( std::ostream& os ) { this->printNode_p(); } void printNode_p( std::ostream& os ) { os << (*this); } }; There is a container which stores the base class pointers. I want to use boost::bind function to call the overloaded infix operator in each of its derived class. I have written like this std::vector<A*> m_args .... std::ostream os; for_each( m_args.begin(), m_args.end(), bind(&A::printNode, _1, os) ); What is the problem with this code? Thanks, Gokul.

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  • Is it possible to override the default logging for Glassfish v3?

    - by kgrad
    Related to this question. It appears that Glassfish is exporting slf4j into my application and overriding my logging solution. Is it possible for me to override Glassfish's logging and have my own logging solution take precedence? After searching, I have only found ways to modify the log using logging.properties. I am not married to my current implementation, but I am interested in making it work. thanks.

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  • Enumerate shared folders on Windows with low privileges

    - by Phil Nash
    Using C++ (VS2008) I need to be able to enumerate all shared folders on the current machine and get or construct the local and remote names. We've been using NetShareEnum for this fairly successfully, but have hit a problem where we need to run with a user account with low privileges. To get the local path using NetShareEnum we need to retrieve at least SHARE_INFO_2 structures - but that requires "Administrator, Power User, Print Operator, or Server Operator group membership". I've been trying to use WNetOpenEnum and WNetEnumResource instead but I don't seem to be getting the local name back for that for shares either - and I can't seem to get it to enumerate just local resources - it goes off and finds all shared resources on the local network - which is not an acceptable overhead. So I'd either like help on where I'm going wrong with WNetEnumResource, or a suggestion as to another way of doing this. Any suggestions are much appreciated.

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  • Is this an F# quotations bug?

    - by ControlFlow
    [<ReflectedDefinition>] let rec x = (fun() -> x + "abc") () The sample code with the recursive value above produces the following F# compiler error: error FS0432: [<ReflectedDefinition>] terms cannot contain uses of the prefix splice operator '%' I can't see any slicing operator usage in the code above, looks like a bug... :) Looks like this is the problem with the quotation via ReflectedDefinitionAttribute only, normal quotation works well: let quotation = <@ let rec x = (fun() -> x + "abc") () in x @> produces expected result with the hidden Lazy.create and Lazy.force usages: val quotation : Quotations.Expr<string> = LetRecursive ([(x, Lambda (unitVar, Application (Lambda (unitVar0, Call (None, String op_Addition[String,String,String](String, String), [Call (None, String Force[String](Lazy`1[System.String]), [x]), Value ("abc")])), Value (<null>)))), (x, Call (None, Lazy`1[String] Create[String](FSharpFunc`2[Unit,String]), [x])), (x, Call (None, String Force[String](Lazy`1[String]), [x]))], x) So the question is: is this an F# compiler bug or not?

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  • postgres - ERROR: syntax error at or near "COST"

    - by cino21122
    EDIT Taking COST 100 out made the command go through, however, I'm still unable to run my query because it yields this error: ERROR: function group_concat(character) does not exist HINT: No function matches the given name and argument types. You may need to add explicit type casts. The query I'm running is this: select tpid, group_concat(z) as z, group_concat(cast(r as char(2))) as r, group_concat(to_char(datecreated,'DD-Mon-YYYY HH12:MI am')) as datecreated, group_concat(to_char(datemodified,'DD-Mon-YYYY HH12:MI am')) as datemodified from tpids group by tpid order by tpid, zip This function seems to work fine locally, but moving it online yields this error... Is there something I'm missing? CREATE OR REPLACE FUNCTION group_concat(text, text) RETURNS text AS $BODY$ SELECT CASE WHEN $2 IS NULL THEN $1 WHEN $1 IS NULL THEN $2 ELSE $1 operator(pg_catalog.||) ',' operator(pg_catalog.||) $2 END $BODY$ LANGUAGE 'sql' IMMUTABLE COST 100; ALTER FUNCTION group_concat(text, text) OWNER TO j76dd3;

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  • What Causes Boost Asio to Crash Like This?

    - by Scott Lawson
    My program appears to run just fine most of the time, but occasionally I get a segmentation fault. boost version = 1.41.0 running on RHEL 4 compiled with GCC 3.4.6 Backtrace: #0 0x08138546 in boost::asio::detail::posix_fd_set_adapter::is_set (this=0xb74ed020, descriptor=-1) at /home/scottl/boost_1_41_0/boost/asio/detail/posix_fd_set_adapter.hpp:57 __result = -1 'ÿ' #1 0x0813e1b0 in boost::asio::detail::reactor_op_queue::perform_operations_for_descriptors (this=0x97f3b6c, descriptors=@0xb74ed020, result=@0xb74ecec8) at /home/scottl/boost_1_41_0/boost/asio/detail/reactor_op_queue.hpp:204 op_iter = {_M_node = 0xb4169aa0} i = {_M_node = 0x97f3b74} #2 0x081382ca in boost::asio::detail::select_reactor::run (this=0x97f3b08, block=true) at /home/scottl/boost_1_41_0/boost/asio/detail/select_reactor.hpp:388 read_fds = {fd_set_ = {fds_bits = {16, 0 }}, max_descriptor_ = 65} write_fds = {fd_set_ = {fds_bits = {0 }}, max_descriptor_ = -1} retval = 1 lock = { = {}, mutex_ = @0x97f3b1c, locked_ = true} except_fds = {fd_set_ = {fds_bits = {0 }}, max_descriptor_ = -1} max_fd = 65 tv_buf = {tv_sec = 0, tv_usec = 710000} tv = (timeval *) 0xb74ecf88 ec = {m_val = 0, m_cat = 0x81f2c24} sb = { = {}, blocked_ = true, old_mask_ = {__val = {0, 0, 134590223, 3075395548, 3075395548, 3075395464, 134729792, 3075395360, 135890240, 3075395368, 134593920, 3075395544, 135890240, 3075395384, 134599542, 3020998404, 135890240, 3075395400, 134614095, 3075395544, 4, 3075395416, 134548135, 3021172996, 4294967295, 3075395432, 134692921, 3075395504, 0, 3075395448, 134548107, 3021172992}}} #3 0x0812eb45 in boost::asio::detail::task_io_service ::do_one (this=0x97f3a70, lock=@0xb74ed230, this_idle_thread=0xb74ed240, ec=@0xb74ed2c0) at /home/scottl/boost_1_41_0/boost/asio/detail/task_io_service.hpp:260 more_handlers = false c = {lock_ = @0xb74ed230, task_io_service_ = @0x97f3a70} h = (boost::asio::detail::handler_queue::handler *) 0x97f3aa0 polling = false task_has_run = true #4 0x0812765f in boost::asio::detail::task_io_service ::run (this=0x97f3a70, ec=@0xb74ed2c0) at /home/scottl/boost_1_41_0/boost/asio/detail/task_io_service.hpp:103 ctx = { = {}, owner_ = 0x97f3a70, next_ = 0x0} this_idle_thread = {wakeup_event = { = {}, cond_ = {__c_lock = { __status = 0, __spinlock = 22446}, __c_waiting = 0x2bd7, __padding = "\000\000\000\000×+\000\000\000\000\000\000×+\000\000\000\000\000\000\204:\177\t\000\000\000", __align = 0}, signalled_ = true}, next = 0x0} lock = { = {}, mutex_ = @0x97f3a84, locked_ = false} n = 11420 #5 0x08125e99 in boost::asio::io_service::run (this=0x97ebbcc) at /home/scottl/boost_1_41_0/boost/asio/impl/io_service.ipp:58 ec = {m_val = 0, m_cat = 0x81f2c24} s = 8 #6 0x08154424 in boost::_mfi::mf0::operator() (this=0x9800870, p=0x97ebbcc) at /home/scottl/boost_1_41_0/boost/bind/mem_fn_template.hpp:49 No locals. #7 0x08154331 in boost::_bi::list1 ::operator(), boost::_bi::list0 (this=0x9800878, f=@0x9800870, a=@0xb74ed337) at /home/scottl/boost_1_41_0/boost/bind/bind.hpp:236 No locals. #8 0x081541e5 in boost::_bi::bind_t, boost::_bi::list1 ::operator() (this=0x9800870) at /home/scottl/boost_1_41_0/boost/bind/bind_template.hpp:20 a = {} #9 0x08154075 in boost::detail::thread_data, boost::_bi::list1 ::run (this=0x98007a0) at /home/scottl/boost_1_41_0/boost/thread/detail/thread.hpp:56 No locals. #10 0x0816fefd in thread_proxy () at /usr/lib/gcc/i386-redhat-linux/3.4.6/../../../../include/c++/3.4.6/bits/locale_facets.tcc:2443 __ioinit = {static _S_refcount = , static _S_synced_with_stdio = } ---Type to continue, or q to quit--- typeinfo for common::RuntimeException = {} typeinfo name for common::RuntimeException = "N6common16RuntimeExceptionE" #11 0x00af23cc in start_thread () from /lib/tls/libpthread.so.0 No symbol table info available. #12 0x00a5c96e in __init_misc () from /lib/tls/libc.so.6 No symbol table info available.

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  • UIButton to intercept UITableView's didSelectRowAtIndexPath method

    - by Michael
    I've got a UIButton on a table cell that is meant to pop up a UIActionSheet but the problem is the didSelectRowAtIndexPath captures that touch and its action takes precedence. Any clever way to override that action when the user touches the button and still have the default action when the user presses elsewhere in the cell? Too bad there is no MoveToFront property.

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  • Using string constants in implicit conversion

    - by kornelijepetak
    Consider the following code: public class TextType { public TextType(String text) { underlyingString = text; } public static implicit operator String(TextType text) { return text.underlyingString; } private String underlyingString; } TextType text = new TextType("Something"); String str = text; // This is OK. But I want to be able do the following, if possible. TextType textFromStringConstant = "SomeOtherText"; I can't extend the String class with the TextType implicit operator overload, but is there any way to assign a literal string to another class (which is handled by a method or something)? String is a reference type so when they developed C# they obviously had to use some way to get a string literal to the class. I just hope it's not hardcoded into the language.

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  • How can I tell if a set of parens in perl code will act as grouping parens or form a list?

    - by Ryan Thompson
    In perl, parentheses are used for overriding precedence (as in most programming languages) as well as for creating lists. How can I tell if a particular pair of parens will be treated as a grouping construct or a one-element list? For example, I'm pretty sure this is a scalar and not a one-element list: (1 + 1) But what about more complex expressions? Is there an easy way to tell?

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  • Nonstandard SSIS lookup

    - by Stefan
    I have a situation where I am trying to lookup a value in one table based on values in another table, using a BETWEEN operator and not an = operator. In one table, I have a value "EffectiveDate". I want to get a Weight number from another table, but the other table has two fields: "Inception" and "Termination". What I want to do is extract the Weight from that table for use where the EffectiveDate is between Inception and Termination. SSIS doesn't seem to provide a way to do this. It's good at matching one column to another column, but doesn't seem to allow one to many-column comparison/operations. Am I missing anything? Is this possible to do somehow?

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  • python: iif or (x ? a : b)

    - by Albert
    If Python would support the (x ? a : b) syntax from C/C++, I would write: print paid ? ("paid: " + str(paid) + " €") : "not paid" I really don't want to have an if-check and two independent prints here (because that is only an example above, in my code, it looks much more complicated and would really be stupid to have almost the same code twice). However, Python does not support this operator or any similar operator (afaik). What is the easiest/cleanest/most common way to do this? I have searched a bit and seen someone defining an iif(cond,iftrue,iffalse) function, inspired from Visual Basic. I wondered if I really have to add that code and if/why there is no such basic function in the standard library.

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  • Creating an AST node in Erlang

    - by dagda1
    Hi, I am playing about with Erlang and I am trying to write a simple arithmetic parser. I want to try and parse the following expression: ((12+3)-4) I want to parse the expression into a stack of AST nodes. When parsing this expression, I would first of all create a binary expression for the (12+3) expression which would look something like this in C#: var binaryStructure = new BinaryStructure(); binaryStructure.Left = IntegerLiteralExpression(12); binaryStructure.Right = IntegerLiteralExpression(4); binaryStructure.Operator = binaryExpression.Operator != BinaryOperatorType.Addition; I am quite new to Erlang and I am wondering how I would go about creating a structure like this in Erlang that I can place on a List that I would use as the stack of expressions. Can anyone suggest how to create such a tree like structure? Would a function be a good fit? Thanks Paul

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  • May volatile be in user defined types to help writing thread-safe code

    - by David Rodríguez - dribeas
    I know, it has been made quite clear in a couple of questions/answers before, that volatile is related to the visible state of the c++ memory model and not to multithreading. On the other hand, this article by Alexandrescu uses the volatile keyword not as a runtime feature but rather as a compile time check to force the compiler into failing to accept code that could be not thread safe. In the article the keyword is used more like a required_thread_safety tag than the actual intended use of volatile. Is this (ab)use of volatile appropriate? What possible gotchas may be hidden in the approach? The first thing that comes to mind is added confusion: volatile is not related to thread safety, but by lack of a better tool I could accept it. Basic simplification of the article: If you declare a variable volatile, only volatile member methods can be called on it, so the compiler will block calling code to other methods. Declaring an std::vector instance as volatile will block all uses of the class. Adding a wrapper in the shape of a locking pointer that performs a const_cast to release the volatile requirement, any access through the locking pointer will be allowed. Stealing from the article: template <typename T> class LockingPtr { public: // Constructors/destructors LockingPtr(volatile T& obj, Mutex& mtx) : pObj_(const_cast<T*>(&obj)), pMtx_(&mtx) { mtx.Lock(); } ~LockingPtr() { pMtx_->Unlock(); } // Pointer behavior T& operator*() { return *pObj_; } T* operator->() { return pObj_; } private: T* pObj_; Mutex* pMtx_; LockingPtr(const LockingPtr&); LockingPtr& operator=(const LockingPtr&); }; class SyncBuf { public: void Thread1() { LockingPtr<BufT> lpBuf(buffer_, mtx_); BufT::iterator i = lpBuf->begin(); for (; i != lpBuf->end(); ++i) { // ... use *i ... } } void Thread2(); private: typedef vector<char> BufT; volatile BufT buffer_; Mutex mtx_; // controls access to buffer_ };

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  • How Do I Loop Through a Date Range in Reverse?

    - by Russ Bradberry
    I have a date range that I would like to be able to loop through in reverse. Give the following, how would I accomplish this, the standard Range operator doesn't seem t be working properly. >> sd = Date.parse('2010-03-01') => Mon, 01 Mar 2010 >> ed = Date.parse('2010-03-05') => Fri, 05 Mar 2010 >> (sd..ed).to_a => [Mon, 01 Mar 2010, Tue, 02 Mar 2010, Wed, 03 Mar 2010, Thu, 04 Mar 2010, Fri, 05 Mar 2010] >> (ed..sd).to_a => [] as you can see, the range operator works properly form start to end, but not from end to start.

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  • Passing const CName as this argument discards qualifiers

    - by Geno Diaz
    I'm having trouble with passing a constant class through a function. // test the constructors auto CName nameOne("Robert", "Bresson"); const CName nameTwo = nameOne; auto CName nameThree; // display the contents of each newly-constructed object... // should see "Robert Bresson" cout << "nameOne = "; nameOne.WriteFullName(); cout << endl; // should see "Robert Bresson" again cout << "nameTwo = "; nameTwo.WriteFullName(); cout << endl; As soon as the compiler hits nameTwo.WriteFullName() I get the error of abandoning qualifiers. I know that the class is a constant however I can't figure out how to work around it. The function is in a header file written as so: void const WriteFullName(ostream& outstream = cout) { outstream << m_first << ' ' << m_last; } I receive this error when const is put in back of the function header main.cpp:(.text+0x51): undefined reference to CName::CName()' main.cpp:(.text+0x7c): undefined reference toCName::WriteFullName(std::basic_ostream &) const' main.cpp:(.text+0xbb): undefined reference to CName::WriteFullName(std::basic_ostream<char, std::char_traits<char> >&) const' main.cpp:(.text+0xf7): undefined reference toCName::WriteFullName(std::basic_ostream &) const' main.cpp:(.text+0x133): undefined reference to operator>>(std::basic_istream<char, std::char_traits<char> >&, CName&)' main.cpp:(.text+0x157): undefined reference tooperator<<(std::basic_ostream &, CName const&)' main.cpp:(.text+0x1f4): undefined reference to operator<<(std::basic_ostream<char, std::char_traits<char> >&, CName const&)' main.cpp:(.text+0x22b): undefined reference tooperator<<(std::basic_ostream &, CName const&)' main.cpp:(.text+0x25f): undefined reference to operator<<(std::basic_ostream<char, std::char_traits<char> >&, CName const&)' main.cpp:(.text+0x320): undefined reference tooperator<<(std::basic_ostream &, CName const&)' main.cpp:(.text+0x347): undefined reference to `operator(std::basic_istream &, CName&)'

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  • Accessing structure elements using pointers

    - by Arun Nadesh
    Hi Everybody, Greetings! I got surprised when the following program did not crash. typedef struct _x{ int a; char b; int c; }x; main() { x *ptr=0; char *d=&ptr->b; } As per my understanding the -> operator has higher precedence over & operator. So I expected the program to crash at the below statement when we try to dereference the NULL pointer tr. char *d=&ptr->b; But the statement &ptr->b evaluates to a valid address. Could somebody please explain where I'm wrong? Thanks & Regards, Arun

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  • sOperator as and generic classes

    - by abatishchev
    I'm writing .NET On-the-Fly compiler for CLR scripting and want execution method make generic acceptable: object Execute() { return type.InvokeMember(..); } T Execute<T>() { return Execute() as T; /* doesn't work: The type parameter 'T' cannot be used with the 'as' operator because it does not have a class type constraint nor a 'class' constraint */ // also neither typeof(T) not T.GetType(), so on are possible return (T) Execute(); // ok } But I think operator as will be very useful: if result type isn't T method will return null, instead of an exception! Is it possible to do?

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  • IMB_ibImageFromMemory: unknown fileformat?

    - by Antoni4040
    Here's my add-on: import bpy import os import sys import subprocess import threading class ExportToGIMP(bpy.types.Operator): bl_idname = "uv.exporttogimp" bl_label = "Export to GIMP" def execute(self, context): self.filepath = os.path.join(os.path.dirname(bpy.data.filepath), "Layout") bpy.ops.uv.export_layout(filepath=self.filepath, check_existing=True, export_all=False, modified=False, mode='PNG', size=(1024, 1024), opacity=0.25, tessellated=False) self.files = os.path.dirname(bpy.data.filepath) cmd = " (python-fu-bgsync RUN-NONINTERACTIVE)" subprocess.Popen(['gimp', '-b', cmd]) self.update() return {'FINISHED'}; def update(self): self.thread = threading.Timer(3.0, self.update).start() self.filepath2 = "/home/antoni4040/????afa/Layout1.png" bpy.ops.image.open(filepath=self.filepath2, filter_blender=False, filter_image=True, filter_movie=False, filter_python=False, filter_font=False, filter_sound=False, filter_text=False, filter_btx=False, filter_collada=False, filter_folder=True, filemode=9, relative_path=False) tex = bpy.data.textures.new(name = self.filepath2, type = "IMAGE") def exporttogimp_menu(self, context): self.layout.operator(ExportToGIMP.bl_idname, text="Export To GIMP") bpy.utils.register_class(ExportToGIMP) bpy.types.IMAGE_MT_uvs.append(exporttogimp_menu) But I can't load an image, because I get this: Reached EOF while decoding PNG IMB_ibImageFromMemory: unknown fileformat (/home/antoni4040/????afa/Layout1.png) What is that?

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  • Why does SFINAE not apply to this?

    - by Simon Buchan
    I'm writing some simple point code while trying out Visual Studio 10 (Beta 2), and I've hit this code where I would expect SFINAE to kick in, but it seems not to: template<typename T> struct point { T x, y; point(T x, T y) : x(x), y(y) {} }; template<typename T, typename U> struct op_div { typedef decltype(T() / U()) type; }; template<typename T, typename U> point<typename op_div<T, U>::type> operator/(point<T> const& l, point<U> const& r) { return point<typename op_div<T, U>::type>(l.x / r.x, l.y / r.y); } template<typename T, typename U> point<typename op_div<T, U>::type> operator/(point<T> const& l, U const& r) { return point<typename op_div<T, U>::type>(l.x / r, l.y / r); } int main() { point<int>(0, 1) / point<float>(2, 3); } This gives error C2512: 'point<T>::point' : no appropriate default constructor available Given that it is a beta, I did a quick sanity check with the online comeau compiler, and it agrees with an identical error, so it seems this behavior is correct, but I can't see why. In this case some workarounds are to simply inline the decltype(T() / U()), to give the point class a default constructor, or to use decltype on the full result expression, but I got this error while trying to simplify an error I was getting with a version of op_div that did not require a default constructor*, so I would rather fix my understanding of C++ rather than to just do what works. Thanks! *: the original: template<typename T, typename U> struct op_div { static T t(); static U u(); typedef decltype(t() / u()) type; }; Which gives error C2784: 'point<op_div<T,U>::type> operator /(const point<T> &,const U &)' : could not deduce template argument for 'const point<T> &' from 'int', and also for the point<T> / point<U> overload.

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  • Which are your favorite programming language gadgets?

    - by FerranB
    There are some gadgets/features for programming languages that I like a lot because they save a lot of coding or simply because they are magical or nice. Some of my favorites are: C++ increment/decrement operator: my_array[++c]; C++ assign and sum or substract (...): a += b C# yield return: yield return 1; C# foreach: foreach (MyClass x in MyCollection) PLSQL for loop: for c in (select col1, col2 from mytable) PLSQL pipe row: for i in 1..x loop pipe row(i); end loop; Python Array access operator: a[:1] PLSQL ref cursors. Which are yours?

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