error , Symbol 'vector' could not be resol

问题:

I am using eclipse in linux to develop a c++ application and I am getting this editor annotation error "Symbol 'vector' could not be resolved" from the following code lines

std::vector<unsigned char> buffer;

I feel that some library is missing or the paths are not set. I explicitly downloaded STL but its of no use. Do I have to re install GCC on my linux ?

回答1:

In Eclipse, right-click on the project name...Select Index...Rebuild.

回答2:

I had the same issue. I believe the problem arises from how std:: autocompletion is updated. Eclipse should be getting this from the Path and Symbols, but it could be buggy. I had to clean all Eclipse settings after upgrading gcc (thus, g++), since you're in Linux it's under your home folder ~/.eclipse/.

Thus,

1) Re-started Eclipse after cleaning ~/.eclipse/.

2) checked that Path and Symbols (under right-click on project > General > Path and Symbols) included all the upgraded gcc and c++ include directories (vector should be under ./gcc/version/include/c++/version/)

3) Rebuild index.

4) Created a *.cpp file that includes the *.h where the error is showing. This will force Eclipse to backtrace dependencies for *.h.

5) Rebuild index and/or restart a few times as required, now I can see vector at the end of std:: autocompletion.

(see picture)

Hope it helps!

回答3:

You need to include the STL vector definition in your program. Put:

#include <vector>

at the top of your file and it should work.

回答4:

See Also related question: Eclipse CDT: Symbol 'cout' could not be resolved

for me the problem was that in #include <vector> somewhere there is #include <bits/c++config> which has a different include path than #include <vector>

i.e.: /usr/include/c++/4.6/x86_64-linux-gnu

回答5:

#include<vector>

should be included at top.

回答6:

#include <vector>

Also, std::vector is template type, so you have to use it like

std::vector<char> buffer;

回答7:

I feel that some library is missing or the paths are not set.

Yes, this sounds like a linker error. Linkers deal with symbols.

I explicitly downloaded STL but its of no use.

Hopefully you mean libstdc++, GNU's implementation of the C++ Standard Library, and you probably shouldn't have done this. Your toolchain comes with the proper stdlib implementation.

Do I have to re install GCC on my linux?

Probably wise. And let this installation handle the standard library.

Also, on the off-chance that you're playing with your compilation command line, remember to invoke g++ not gcc; g++ automatically links in the C++ runtimes and stdlib implementation, whereas gcc is designed for C.

回答8:

Created a *.cpp file that includes the *.h where the error is showing. This will force Eclipse to backtrace dependencies for *.h.
Is working for me...

回答9:

Most likely you have some system-specific include directories missing in your settings which makes it impossible for indexer to correctly parse iostream, thus the errors. Selecting Index -> Search For Unresolved Includes in the context menu of the project will give you the list of unresolved includes which you can search in /usr/include and add containing directories to C++ Include Paths and Symbols in Project Properties.

On my system I had to add /usr/include/c++/4.6/x86_64-linux-gnu for bits/c++config.h to be resolved and a few more directories.

Don't forget to rebuild the index (Index -> Rebuild) after adding include directories.

回答10:

Apparently vector belongs to C++ standard template library from MinGW perspective. so in addition to

 #include <vector>

Add

using namespace std;

after the header file inclusions.

回答11:

I know that this problem was already solved, but it still appears as the top result on Google.

Using Eclipse Neon for Linux I solved it with Quick Fix:

• right click at "vector" in the editor,
• then "Quick Fix"

回答12:

adding #include< vector > and using namespace std; solved my problem