For my current project, I needed to convert from String^ to std::string and vice-versa a lot. I read I could accomplish that by marshaling (from what I've read it's a process of conversion between native and managed data types because they are handled differently in the memory).
I read the instructions off of this topic. I put the code in a button event. Since I'm a beginner, I didn't really know which file do I need to include <msclr\marshal_cppstd.h> in. After reading pre-made descriptions in each of the files, I included the library in stdafx.h, which produced the following errors:
error C2065: 'marshal_as' : undeclared identifier
error C2275: 'std::string' : illegal use of this type as an expression
When including it in the main .cpp and stdafx.cpp files, one of the errors I get is:
error C2872: 'IServiceProvider' : ambiguous symbol
even though I included the file before any "using" directive, as advised here.
Thanks in advance.
Related
I was unable to find following vim completer feature. Say you write a code and you specify a type before including appropriate header file defining this type e.g.:
int main(){
uint8_t a = 0, b = 5;
...
return 0;
}
What you end up with is:
use of undeclared identifier 'uint8_t'
warning in VIM (I use YouCompleteMe) and a compilation error:
error: unknown type name ‘uint8_t’
What I'm looking for is a completer that suggests you something like
use of undeclared identifier 'uint8_t' did you include stdint.h?
If no such feature exists so far, what is the reason?
In lh-cpp I had a small feature, that given a ctags database will be able to add the inclusion statement related to the symbol under the cursor. Now I've extracted the feature to lh-dev.
I also remember to have defined an associative map that knows where a few symbols from the standard library come from, so far I only use it to automatically add the inclusion statement for types we inherit from in my C++ class snippets. What is sure, is that it could also be used for fixing missing includes (not everybody want to parse the standard library with ctags).
Note however, my scripts don't try to automatically detect all missing includes to add them. It's much too complex in real C++ projects.
You may need to add directory path to the -I option list of your compiler, or add the directory path to VIM's path option variable
:help 'path
If you don't know wich path to include, locate stdint.h could be a good start.
Related Link.
I'm trying to write an x2 camera driver for a Hamamatsu camera in Visual Studio 2015. The X2 driver template already has windows.h included as an external dependency, but when trying to include a necessary header file, it throws an error that windows.h is not included (along with 80 or so errors of function calls that therefore don't exist). But when I include windows.h, I think it's causing a double include and is throwing this error:
Severity: Error (active)
Code: none
Description: expected an identifier Project :x2camera
File: c:\Program Files (x86)\Windows Kits\10\Include\10.0.10586.0\um\winnt.h
Line: 524
I'm really new to working with Visual Studio projects - how can I include windows.h into the file so it can get the functions and declarations it needs without actually including it and causing a double inclusion? Like I said, it's in the "project dependencies" list, and I think it's being included in another file (but I'm having a hard time finding that).
Or is that not even my problem?
Any help is appreciated.
No idea what the problem was but I somehow managed to get it to compile. I think it needed to be included elsewhere first, then built, then included where it needed to be... which doesn't make sense honestly but maybe it was an error with how the inclusion was functioning.
Either way, my question is now resolved, though the questions that now arise such as "why the heck did this work" are baffling.
Is there any way to convert System::String to std::string if I am not allowed to use msclr/marshal_cppstd.h?
The reason is that I need to use cryptlib.h in the same project and I get an error when I include both:
cryptlib.h and wincrypt.h can't both be used at the same time due to conflicting type names
The error is telling you the problem is cryplib.h and wincrypt.h cannot be #included into the same source file. I think the text of the message comes from whatever comes after the #error, which is down to the user - see here.
So, if you can't included them into the same source file, you could partition up your code differently and include them in different source files. Marshalling the string is not what the error message is complaining about.
I'm having some real difficulties porting a really old Visual Studio 97 C++ project to Visual Studio 2010. Let me begin by first giving a little background on the errors I was getting immediately prior to this new LNK1224 error because they may be related, but I'm not sure.
Prior to my new error I was receiving this error:
error LNK2005: "void __cdecl operator delete(void *)" (??3#YAXPAX#Z) already defined in LIBCMT.lib(delete.obj) nafxcw.lib(afxmem.obj)
Through some digging I found that the reason for this error was because both the MFC and CRT libraries contain definitions for "new" and "delete" so they were colliding. Microsoft provides 2 solutions for this detailed in http://support.microsoft.com/kb/q148652/ . One of them was to make sure that in all your files you always include the MFC headers (afx stuff) first. Well there are about 100 files in this project and I just got tired of trying to find the files that were including resources in the wrong order. So I went with the other solution which is basically forcing libraries to load in a particular order. Basically you have to tell the compiler to ignore a particular library so that you can load it explicitly your self in the order that you choose. In my case, it was nafxcw.lib.
So under Project Properties --> Linker --> Input, I explicitly ignored nafxcw.lib and then explicitly included it at the front of the list.
So after doing this, my LNK2005 errors went away. But they were replaced with one single link error.
error LNK1224: invalid image base 0x287600000
I don't know if I fixed my previous link errors correctly and this new link error is in fact the next thing I have to deal with, or I simply created a more critical link error that is basically stopping the linking process before it gets to my original LNK2005 errors. In either case, there isn't much information I could find on this error. Microsoft doesn't say much in this link about it http://msdn.microsoft.com/en-us/library/3ya3f8wz%28v=vs.80%29.aspx
You specified an invalid base address for the image. Base addresses must be 64KB aligned (the last four hex digits must be zero) and image base must fit within a 32-bit signed or unsigned value.
This isn't all that helpful to me and there seems to be no other clues as to where this problem is coming from. I don't know what the next step is.
OK, so it looks like I have solved my own problem. Here is what I did. I needed to know where the heck this number was coming from so I simply used Notepad++ to do a word search through all the project files looking for "2876" which I got from the error message "LINK : fatal error LNK1224: invalid image base 0x287600000". I found that in the project file (.vcxproj) had the following entry in it:
<BaseAddress>0x287600000</BaseAddress>
So I opened it up and sat there wondering how this number was wrong. I mean I don't even know what this field is for. I didn't even generate this file, M$ made it. Why would the IDE create it's own input file incorrectly? Anyways, as I was trying to google this "BaseAddress" item to figure out what it was, it dawned on me that it looked like there were too many zero's. So I went back and counted and sure enough, this wasn't a 32-bit number, it was a 36-bit number. Deleted one of the zero's, recompiled, and boom it worked. Low and behold, that's kind of what the defintion I looked up, mentioned in the problem statement, hinted at looked up earlier on MSDN but it didn't click.
I don't make a habit to rummage through auto generated files very often so I never questioned that this may be the problem.
I already included Rpc.h, but I am still receiving error LNK2019: unresolved external symbol __im__RpcServerListen#12 referenced in function _main. Is there anything else I need to do to be able to call this function?
It's not enough to include the header file, that just tells the compiler about the types, functions and so on, that you want to use.
You also have to link with the relevant object files or libraries since they contain the actual code that you will be calling. You can tell this because the error starts with LNK, meaning you have a linker issue rather than a compiler one.
The actual files that you need to link to should be specified for the linking phase. For Windows RPC, this appears to be rpcrt4.lib (see here).