I am working on an Android application that uses OpenCV 2.4.9 and NDKr9 as dependecies. I also use Eclipse 4.4 Luna as the IDE, with CDT plugin 8.4 installed.
Whenever I'm trying to use the methods std::vector.at(int), or the "[]" method, i get weird errors. For instance, consider the code:
#include <vector>
.........................
struct CustomStruct {
int level;
Point firstPoint, secondPoint, middlePoint;
};
.........................
int maxElemNr = 10;
std::vector<CustomStruct > customStructVector(maxElemNr);
.........................
for(int i=0;i<customStructVector.size();i++){
if(customStructVector.at(i).level == 0){
}
}
At customStructVector.at(i) Eclipse tells me the following:
Invalid arguments ' Candidates are: ResultWithEvidence & at(?) const
ResultWithEvidence & at(?)'
If I want to use the "[]" operator, instead of the "at(index)" method, i get the following:
resultWithEvidenceVector[i].level tells me that the field level is not found.
I am by no means an expert C/C++ coder, and I am rather new at working with the NDK. Coming from a Java background, I was expecting to get an object of type CustomStruct when calling either customStructVector.at(i) or customStructVector[i], such that I could then simply access the field level on my object, to read its value.
Also, declaring my vector as
int maxElemNr = 10;
std::vector<CustomStruct> customStructVector;
customStructVector.reserve(maxElemNr);
I get:
Invalid arguments ' Candidates are: void reserve(?) '
I have searched for answers, and came with the theory that eclipse might not use the c++11 version of the std library?
I've read about the vector class from here. Also, this issue closely resembles the question asked here.
Will provide more info about my environment and such, if needed. Would like to solve this, as it's quite a blocker for my project as of now..
What am I doing wrong? I had no problems compiling and running the code previously to using the std::vector class.
LE: apparently the workaround &(resultWithEvidenceVector.data()+i)->level is recognized by the editor, and the code compiles. Would still like to use the std::vector as it is supposed to be used though.
I had the same problem. It works in Visual Studio compiler but when i try to access vector element i get exactly the same error.
However it seems that if you don't use 'at' then it works for example customStructVector.at(i) use customStructVector(i),
It is strange. I didn't test it in detail. Please note that if you have vector you have to cast the result in order to access the type members.
Regards
Related
I'm trying to use Visual Studio Code to develop Fortran MPI programs. However, while I can successfully build and run them just fine, it would be very helpful for me if I can use intellisense/autocompletion features for MPI (as well as other external modules). I have /usr/lib/openmpi/ (which contains mpi_f08.mod) as part of fortran.includePaths in my settings.json. However, when I use mpi_f08, I get the problem message from VS Code Module "mpi_f08" not found in project. Here is a minimal CMake build example:
! hello.f90
program hello
use mpi_f08
implicit none
integer :: ierror, nproc, my_rank
call MPI_Init()
call MPI_Comm_size(MPI_COMM_WORLD, nproc, ierror)
call MPI_Comm_rank(MPI_COMM_WORLD, my_rank, ierror)
print*, "hello from rank ", my_rank
call MPI_Finalize()
end program hello
# CMakeLists.txt
cmake_minimum_required(VERSION 3.12)
project(hello_mpi)
enable_language(Fortran)
find_package(MPI REQUIRED)
add_executable(hello_mpi hello.f90)
include_directories(${MPI_Fortran_INCLUDE_PATH})
target_link_libraries(hello_mpi PUBLIC ${MPI_Fortran_LIBRARIES})
I would like to be able to (i) get rid of the warning/message and more importantly (ii) enable suggestions from MPI when I press CTRL+space as it would if I was calling from an internal module.
I'll post a partial answer since it's better than nothing, hopefully this helps someone else and/or enables someone else to answer my question fully.
It seems the issue relates to the Fortran language server, which can be configured by adding a .fortls JSON file, as explained on its Github README: https://github.com/hansec/fortran-language-server
I added the following, which allowed it to find not only local modules but also MPI (and the external module json-fortran):
{
"source_dirs": ["src", "."],
"ext_source_dirs": [
"/path/to/json-fortran/src",
"/path/to/openmpi-4.1.2/ompi/mpi/fortran/use-mpi-f08",
]
}
This doesn't capture all functions in json-fortran, which I think is because of its .inc files, as it doesn't give me function pointers like json_file::get at autocomplete.
As for MPI, this kind of works, as it gives me all the functions I can think of needing, but with _f08 appended to the end of it. I don't know the inner workings of OpenMPI but I guess e.g. MPI_Init wraps MPI_Init_f08 for reasons of backward compatibility. For now I can simply autocomplete to the _f08 version and remove that bit manually. (I also tried adding openmpi-4.1.2/ompi/mpi/fortran/use-mpi-tkr and openmpi-4.1.2/ompi/mpi/fortran/mpif.h but no luck).
Would be nice to get this detail sorted though. It is also mildly annoying that I must manually include the source dirs now (removing it makes it not find local modules).
I'm writing some C++ code with eclipe.
I have a strange behavior with vector objects.
When I use the method resize for example, Eclipse returns the following error:
#include "vector"
...
vector<int> a;
a.resize(5);
Error: Invalid arguments candidates are: void resize(?, int).
However the code compiles from command line.
How can I fix this fastidious behavior of eclipse?
After quite a while searching and tinkering with settings, I think I have found an answer. To get the indexer parsing the code correctly I had to:
Right click the project -> Properties
Go to C/C++ General -> Preprocessor Include Paths, Macros etc.
Click the providers tab
Check the CDT GCC Build-in Compiler Settings option
Apply
Rebuild index
I am developing an eclipse plugin that runs code violation checker on the difference of two versions of a file. Right now I am using diff.exe to get the difference between the two files. But as diff.exe is an extrenal app, I realized that its better to use eclipse built-in compare tool to get the file difference.
So I used org.eclipse.compare and reached up to this point:
public static List<Patch> compare(String old, String recent) {
try{
IRangeComparator left = new TokenComparator(old); //what exactly to be passed in this constructor, a file path, a literal value or something else?
IRangeComparator right = new TokenComparator(recent);
RangeDifference[] diffs = RangeDifferencer.findDifferences(left, right); // This line is throwing NPE
//..
// Process RangeDifferences into Collection of Patch collection
//..
}catch(Exception e){}
//Returns a collection of file differences.
return null;
}
Now the problem is I am not sure what exactly to be passed in the constructor TokenComparator(String). The document says this constructor Creates a TokenComparator for the given string. But it is not written what exactly to be passed in this constructor, a file path, a literal value or something else? When I'm passing a file path or a string literal I am getting NullPointerException on the next line of finding differences.
java.lang.NullPointerException
at org.eclipse.compare.internal.core.LCS.isCappingDisabled(LCS.java:98)
at org.eclipse.compare.internal.core.LCS.longestCommonSubsequence(LCS.java:55)
at org.eclipse.compare.rangedifferencer.RangeComparatorLCS.longestCommonSubsequence(RangeComparatorLCS.java:186)
at org.eclipse.compare.rangedifferencer.RangeComparatorLCS.findDifferences(RangeComparatorLCS.java:31)
at org.eclipse.compare.rangedifferencer.RangeDifferencer.findDifferences(RangeDifferencer.java:98)
at org.eclipse.compare.rangedifferencer.RangeDifferencer.findDifferences(RangeDifferencer.java:82)
at org.eclipse.compare.rangedifferencer.RangeDifferencer.findDifferences(RangeDifferencer.java:67)
at com.dassault_systemes.eclipseplugin.codemonview.util.CodeMonDiff.compare(CodeMonDiff.java:48)
at com.dassault_systemes.eclipseplugin.codemonview.util.CodeMonDiff.main(CodeMonDiff.java:56)
Someone please tell what is right way to proceed.
If the question is What value the token comparators constructor takes then the answer is it takes the input string to compare. Specified in javadoc here http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fapi%2Forg%2Feclipse%2Fcompare%2Fcontentmergeviewer%2FTokenComparator.html
TokenComparator(String text)
Creates a TokenComparator for the given string.
And the null pointer yo are getting is because in function isCappingDisabled it tries to open the compare plugin which seems to be null. You seem to be missing a direct dependency to the plugin "org.eclipse.compare.core"
The org.eclipse.compare plugin was never meant to be used in standalone : many of its functionalities require a running instance of Eclipse. Furthermore, it mixes core and UI code within the same plugin, which will lead to unexpected behavior if you are not very careful about what you use and what dependencies are actually available in your environment.
You mentionned that you were developping an Eclipse plugin. However, the NPE you get indicates that you are not running your code as an Eclipse plugin, but rather as a standard Java program. In an Eclipse environment, ComparePlugin.getDefault() cannot return null : the plugin needs to be started for that call to return anything but null.... and the mere loading of the ComparePlugin class within Eclipse is enough to start it.
The answer will be a choice :
You need your code to run as a standalone Java program out of Eclipse. In such an event, you cannot use org.eclipse.compare and diff.exe is probably your best choice (or you could switch to an implementation of diff that was implemented in Java in order to be independent of the platform).
You do not need your program to work in a standalone environment, only as an Eclipse plugin. In this case, you can keep the code you're using. However, when you run your code, you have to launch it as a new "Eclipse application" instead of "Java Application". You might want to look at a tutorial on how to develop Eclipse plugins for this, This simple tutorial from Lars Vogel shows how to run a new Eclipse Application to test an Hello World plugin. You will need a similar code, with a menu entry to launch your plugin somewhere (right-click on a file then select "check violations" in your case?).
I need to create a predicate from bound member function, so I wrapped it in a boost::function<bool(SomeObject const &)>. That seems to be fine and everything, but I also needed to negate it in one case. However
boost::function<bool(SomeObject const &)> pred;
std::not1(pred);
does not compile under MSVC++ 9.0 (Visual Studio 2008), complaining that reference to reference is invalid:
C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\functional(213) : warning C4181: qualifier applied to reference type; ignored
C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\functional(213) : error C2529: '_Left' : reference to reference is illegal
The problem is that boost::function defines the argument_type as SomeObject const & and the std::unary_negate<_Fn1> instantiated by std::not1 internally tries to use const typename _Fn1::argument_type& and compiler rejects it because T::argument_type is already a reference. I am certain that that should compile under C++11, but this is old compiler that is C++03 only. So I'd like to know who's fault it is:
the compiler's, because it should collapse the reference (apparently not),
the standard library's, because it should be prepared to handle functors taking references (apparently not, because the specification defines unary_negate with const typename Predicate::argument_type& x argument),
boost's, because argument_type shouldn't be reference even when the actual argument is or
mine, because boost::function shouldn't be used with reference arguments?
The fault is certainly not Boost's; boost::function is basically just std::function, with all the same semantics. And boost::functions with reference parameters work fine, too. You just can't use them with std::not1 or the rest of the <functional> stuff.
C++11's reference-collapsing makes std::not1 work the way you would think it ought to. The way std::not1 was specified in C++03 couldn't possibly work without reference-collapsing — except in implementations where the implementors did a little bit of creative interpretation rather than slavishly following the letter of the Standard.
It's possible to make std::not1 work in C++03 by adding a specialization of std::unary_negate for predicates with reference argument_types, but neither libc++ nor libstdc++ has done so.
But you know who has? Boost! If you just change your code to use boost::not1 everywhere you currently use std::not1, everything will work fine. Basically, think of the boost namespace as if it were a C++11-compliant version of std; anything that works in C++11's std namespace probably works in C++03's boost namespace.
Caveat, hopefully off-topic: The Clang compiler on my Macbook (Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)) silently collapses references even in -std=c++03 mode, so that
typedef const int& ref;
typedef const ref& ref2;
produces no error. When you test your C++03 code, make sure you're not using a compiler with this misfeature.
I have recently switched from Netbeans to Eclipse, and Eclipse is finding syntax errors in my Project lot's of places that Netbeans doesn't and I cannot figure out why. As far as can tell both IDE's are set to use java 1.6. An example of this problem would be as follows (which is actually horrible code but I am working with legacy stuff):
Map map;
map = new Hashtable();
... add some stuff to map
int number = 5;
int status = 7;
assertTrue(number == map.get(status));
The above comes back with "Incompatable operand types int and Object" whereas Netbeans does not complain at all. I do not actually following why this doesn't work (does the int object not get autoboxed to an Integer?) as it works at run time from Netbeans. I am presuming there is a configuration setting somewhere in eclipse?
It looks like autoboxing is disabled. Check that Window->Preferences->Java->Compiler->Errors/Warnings Boxing and unboxing conversion is not set to Error. Also check that Window->Preferences->Java->Installed JRE use JDK\JRE that is at least 1.5.
You can setup compiler-warnings under Window->Preferences->Java->Compiler->Errors/Warnings.
Make also sure you're compiling against the correct Java Version (check if your 1.6 Java is in the build-path and check the JDK Compilance level, see Preferences->Java->Compiler)
Change declaration to
Map<Integer,Integer> map;
map = new Hashtable<Integer,Integer>();
and this will solve you problem.
Alternatively, you can change this line
assertTrue(Integer.valueOf(number) == map.get(status));
Comparing Integer with == is not good practice. It is working just occasionally. You really should use equals() instead.
I don't why autoboxing in your case doesn't occurs automatically, maybe somebody that know spec better could provide answer.
P.S. Even better change this to
assertEquals(number, map.get(status));
and this will work as expected.
After clarifications that it is legacy code, my advice is the following. Change your code to:
Map map;
map = new Hashtable();
... add some stuff to map
Integer number = Integer.valueOf(5);
Integer status = Integer.valueOf(7);
assertEquals(number, map.get(status));
(I would even define temporary variable of type Integer where I put result of map.get(status), but it is question of the style whether to do this; This will help compiler though). Here, no new features is used.
Why you don't have problem with the Netbeans? My guess is because your version of JRE (or vendor) or your project settings.