From https://cmake.org/pipermail/cmake/2008-November/025448.html:

&gt; Armin Berres — 11/22/2008, 3:12:41 PM
&gt; 
&gt; ZERO_CHECK will rerun cmake. You can/should execute this after
&gt; changing something on your CMake files.
&gt; 
&gt; ALL_BUILD is simply a target which builds all and everything project
&gt; in the active solution, I guess one can compare it to &quot;make all&quot;.



Add the following line to you CMakeLists.txt to suppress generation of ZERO_CHECK:

    set(CMAKE_SUPPRESS_REGENERATION true)



I&#39;m new to Go and I&#39;m trying to set up a Go project with minimal documentation: https://github.com/alphagov/metadata-api

I&#39;ve cloned it, but when I try `go build` I get the following warnings: 

    main.go:8:2: cannot find package &quot;github.com/Sirupsen/logrus&quot; in any of:
    	/usr/local/Cellar/go/1.3.3/libexec/src/pkg/github.com/Sirupsen/logrus (from $GOROOT)
    	/Users/me/go/src/github.com/Sirupsen/logrus (from $GOPATH)
    main.go:14:2: cannot find package &quot;github.com/alphagov/metadata-api/content_api&quot; in any of:
    	/usr/local/Cellar/go/1.3.3/libexec/src/pkg/github.com/alphagov/metadata-api/content_api (from $GOROOT)
    	/Users/me/go/src/github.com/alphagov/metadata-api/content_api (from $GOPATH)

I&#39;m guessing this is because I haven&#39;t installed the Go equivalent of requirements? 

My `GOPATH` is set:

    metadata-api$ echo $GOPATH
    /Users/me/go

And the Go executable is in 

    metadata-ape$ echo $PATH
    ....:/Users/me/go/bin

What do I need to do to help Go find these packages?

How do I install requirements in Go? &quot;cannot find package&quot;

I am trying to run emulator on my android studio 8.14. When I click run it says it is already running. Any help would be appreciated.



&gt; AVD api21 is already running.
&gt;
&gt; If that is not the case, delete the files at /home/sayem/.android/avd/api21.avd/*.lock and try again

![image containing the error written out above][1]


  [1]: http://i.stack.imgur.com/OVzS7.png

Android Studio : emulator is already running

I&#39;ve created a simple CMakeLists.txt:

    cmake_minimum_required(VERSION 2.8)
    project (HelloWorld)
    add_executable (HelloWorld main.cpp)

When I generate a VS2012 or VS2010 project from CMake, however, I get these 2 additional entries - ALL_BUILD and ZERO_CHECK.
I don&#39;t understand their purpose, do I need them?

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/jVFgk.png

What are ALL_BUILD and ZERO_CHECK and do I need them?

I've created a simple CMakeLists.txt:
<pre><code class="hljs language-scss">cmake_minimum_required(VERSION 2.8)
project (HelloWorld)
add_executable (HelloWorld main.cpp)
</code></pre>
When I generate a VS2012 or VS2010 project from CMake, however, I get these 2 additional entries - ALL_BUILD and ZERO_CHECK.
I don't understand their purpose, do I need them?
<a href="https://i.stack.imgur.com/jVFgk.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/jVFgk.png" alt="enter image description here"></a>

I was surprised when I couldn&#39;t find anything in OpenCV documentation describing - with words - what the various types stand for, and Googling wasn&#39;t much help either. I know that CV_8UC1 is gray-scale, but what does CV_8UC3 stand for? Is it RGB? Or YUV?

Also, what about the other definitions from `types_c.h` (they also lack comments). Is there a pattern to what the naming convention is? Can I interpret from their names to what their features are, like colors, etc.?

    #define CV_8UC1 CV_MAKETYPE(CV_8U,1)
    #define CV_8UC2 CV_MAKETYPE(CV_8U,2)
    #define CV_8UC3 CV_MAKETYPE(CV_8U,3)
    #define CV_8UC4 CV_MAKETYPE(CV_8U,4)
    #define CV_8UC(n) CV_MAKETYPE(CV_8U,(n))
    
    #define CV_8SC1 CV_MAKETYPE(CV_8S,1)
    #define CV_8SC2 CV_MAKETYPE(CV_8S,2)
    #define CV_8SC3 CV_MAKETYPE(CV_8S,3)
    #define CV_8SC4 CV_MAKETYPE(CV_8S,4)
    #define CV_8SC(n) CV_MAKETYPE(CV_8S,(n))
    
    #define CV_16UC1 CV_MAKETYPE(CV_16U,1)
    #define CV_16UC2 CV_MAKETYPE(CV_16U,2)
    #define CV_16UC3 CV_MAKETYPE(CV_16U,3)
    #define CV_16UC4 CV_MAKETYPE(CV_16U,4)
    #define CV_16UC(n) CV_MAKETYPE(CV_16U,(n))
    
    #define CV_16SC1 CV_MAKETYPE(CV_16S,1)
    #define CV_16SC2 CV_MAKETYPE(CV_16S,2)
    #define CV_16SC3 CV_MAKETYPE(CV_16S,3)
    #define CV_16SC4 CV_MAKETYPE(CV_16S,4)
    #define CV_16SC(n) CV_MAKETYPE(CV_16S,(n))
    
    #define CV_32SC1 CV_MAKETYPE(CV_32S,1)
    #define CV_32SC2 CV_MAKETYPE(CV_32S,2)
    #define CV_32SC3 CV_MAKETYPE(CV_32S,3)
    #define CV_32SC4 CV_MAKETYPE(CV_32S,4)
    #define CV_32SC(n) CV_MAKETYPE(CV_32S,(n))
    
    #define CV_32FC1 CV_MAKETYPE(CV_32F,1)
    #define CV_32FC2 CV_MAKETYPE(CV_32F,2)
    #define CV_32FC3 CV_MAKETYPE(CV_32F,3)
    #define CV_32FC4 CV_MAKETYPE(CV_32F,4)
    #define CV_32FC(n) CV_MAKETYPE(CV_32F,(n))
    
    #define CV_64FC1 CV_MAKETYPE(CV_64F,1)
    #define CV_64FC2 CV_MAKETYPE(CV_64F,2)
    #define CV_64FC3 CV_MAKETYPE(CV_64F,3)
    #define CV_64FC4 CV_MAKETYPE(CV_64F,4)
    #define CV_64FC(n) CV_MAKETYPE(CV_64F,(n))



What does CV_8UC3 and the other types stand for in OpenCV?

Is there someone who had experience with this error?

    java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file &quot;/data/app/org.swig.simple-2/base.apk&quot;],nativeLibraryDirectories=[/vendor/lib, /system/lib]]] couldn&#39;t find &quot;liborg.swig.simple.example.so&quot;

Error occurs when I load library by this way. 


    static {
        System.loadLibrary(&quot;example&quot;);
    }

I&#39;m sure &#39;example&#39; class is exist in the current folder.

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader

This came up in a code review discussion recently, but without a satisfactory conclusion. The types in question are analogues to the C++ string_view TS. They are simple non-owning wrappers around a pointer and a length, decorated with some custom functions:

    #include &lt;cstddef&gt;

    class foo_view {
    public:
        foo_view(const char* data, std::size_t len)
            : _data(data)
            , _len(len) {
        }
    
        // member functions related to viewing the &#39;foo&#39; pointed to by &#39;_data&#39;.
    
    private:
        const char* _data;
        std::size_t _len;
    };

The question arose as to whether there is an argument either way to prefer to pass such view types (including the upcoming string_view and array_view types) by value or by const reference.

Arguments in favor of pass by value amounted to &#39;less typing&#39;, &#39;can mutate the local copy if the view has meaningful mutations&#39;, and &#39;probably no less efficient&#39;.

Arguments in favor of pass-by-const-reference amounted to &#39;more idiomatic to pass objects by const&amp;&#39;, and &#39;probably no less efficient&#39;.

Are there any additional considerations that might swing the argument conclusively one way or the other in terms of whether it is better to pass idiomatic view types by value or by const reference.

For this question it is safe to assume C++11 or C++14 semantics, and sufficiently modern toolchains and target architectures, etc.


C++ view types: pass by const&amp; or by value?

I have a class `Dimension` which I defined (like all my classes) in a file Dimension.h:

    class Dimension
    {
    public:
    
    	constexpr Dimension() noexcept;
    
    	constexpr Dimension(int w, int h) noexcept;
    
    	int width;
    	int height;
    
    };

I thought I could, like in all my classes, put the definition in a separate Dimension.cpp:


    #include &quot;Dimension.h&quot;

    constexpr Dimension::Dimension() noexcept : width(0), height(0) {}
    
    constexpr Dimension::Dimension(int w, int h) noexcept : width(w), height(h) {}

But when I try to use the class, the compiler tells me:

warning: inline function &#39;`constexpr Dimension::Dimension()`&#39; used but never defined

and while linking:

undefined reference to &#39;`pong::graphics::Dimension::Dimension()`&#39;

(same with the other constructor)

If I define the class in the header like so:

    class Dimension
    {
    public:
    
    	constexpr Dimension() noexcept : width(0), height(0) {}
    
    	constexpr Dimension(int w, int h) noexcept : width(w), height(h) {}
    
    	int width;
    	int height;
    
    };

and omit the .cpp file, everything works fine.

I&#39;m using GCC 4.9.2. Why does separate definition not work?

Is it possible to declare constexpr class in a header and define it in a separate .cpp file?

What difference between these ways of initializing object member variables in C++11 ? Is there another way ?  which way is better (performance) ?:

    class any {
      public:
        obj s = obj(&quot;value&quot;);
        any(){}
    };

Or 

    class any {
      public:
        obj s;
        any(): s(&quot;value&quot;){}
    };

Thanks.

C++11 member initializer list vs in-class initializer?

I am trying to open Visual Studio, but it is giving an error:

&gt;  cannot run when set up is in progress

It was running fine before when I restarted my machine. I have already installed this version from past one year. 

[![screenshot][1]][1]


  [1]: https://i.stack.imgur.com/MSglD.png

Cannot open Visual Studio - throw error &#39;cannot run when setup is in progress&#39;

I create new asp.net mvc project in visual studio 2015.The project has a wwwroot file.What is this? 
![enter image description here][1]


  [1]: http://i.stack.imgur.com/Tdm6h.png

What is wwwroot in asp.net vnext

I tried to install Scrapy for Python 2.7.8 (anaconda 2.1.0) 32-bit using 

    pip install scrapy

And I got this error 

     error: Microsoft Visual C++ 10.0 is required (Unable to find vcvarsall.bat).

I have followed the solutions found in these stackover flow questions. Nothing worked. 

https://stackoverflow.com/questions/26140192/microsoft-visual-c-compiler-for-python-2-7

https://stackoverflow.com/questions/6126737/cant-find-vcvarsall-bat-file

https://stackoverflow.com/questions/2817869/error-unable-to-find-vcvarsall-bat

https://stackoverflow.com/questions/24380442/getting-error-unable-to-find-vcvarsall-bat-when-running-pip-install-numpy-o

https://stackoverflow.com/questions/19830942/pip-install-gives-error-unable-to-find-vcvarsall-bat

https://stackoverflow.com/questions/6551724/how-do-i-point-easy-install-to-vcvarsall-bat/8705722#8705722

https://stackoverflow.com/questions/24783176/pip-install-mysql-python-returns-unable-to-find-vcvarsall-bat

This is the error, and a few lines above and below it:

    copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\readme.txt
    -&gt; build\lib.win32-3.4\lxml\isoschematron\resources\xsl\iso-schematron-xslt1

    running build_ext

    building &#39;lxml.etree&#39; extension

    C:\Python34\lib\distutils\dist.py:260: UserWarning: Unknown distribution opt
    ion: &#39;bugtrack_url&#39;

      warnings.warn(msg)

    error: Microsoft Visual C++ 10.0 is required (Unable to find vcvarsall.bat).


    ----------------------------------------
    Command &quot;C:\Python34\python.exe -c &quot;import setuptools, tokenize;__file__=&#39;C:
    \\Users\\San\\AppData\\Local\\Temp\\pip-build-wp6ei6r9\\lxml\\setup.py&#39;;exec(com
    pile(getattr(tokenize, &#39;open&#39;, open)(__file__).read().replace(&#39;\r\n&#39;, &#39;\n&#39;), __f
    ile__, &#39;exec&#39;))&quot; install --record C:\Users\San\AppData\Local\Temp\pip-kfkzr_67-r
    ecord\install-record.txt --single-version-externally-managed --compile&quot; failed w
    ith error code 1 in C:\Users\San\AppData\Local\Temp\pip-build-wp6ei6r9\lxml


---

I have both Microsoft Visual Studio 12.0, and Microsoft visual C++ compiler package for Python 2.7, both of which have the vcvarsall.bat file. 

---

I have a system variable that is called &#39;VS120COMNTOOLS&#39; and is its path is set to 

    C:\Program Files\Microsoft Visual Studio 12.0\Common7\Tools\

---

I also added both paths to my environment variables. I&#39;ve also tried just adding one, and then the other. My Path looks like this

    C:\Program Files\Java\jdk1.7.0_25\bin;\Python27;\Python2\python.exe;C:\Python27\Scripts\;C:\Users\San\AppData\Local\Programs\Common\Microsoft\Visual C++ for Python\9.0\;C:\Program Files\Microsoft Visual Studio 12.0\VC\;

---

I also updated by my setup tools (I think to version 8), which should autodetect Microsoft Visual C++ Compiler for Python 2.7. However, I&#39;m still getting the same error. 

---

I have also tried using 

    easy_install scrapy

And I get this error

    error: Setup script exited with error: Microsoft Visual C++ 10.0 is required (Un
able to find vcvarsall.bat).

---

I also have the following in my registry


    HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\9.0\Setup\VC\ProductDir
    HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\12.0\Setup\VC\ProductDir



Python Pip install Error: Unable to find vcvarsall.bat. Tried all solutions

I am attempting to publish and consume versioned NuGet packages of class libraries while avoiding headaches for local development. Here is a sample Visual Studio solution layout:

    | Libraries
      | LibraryA
      | LibraryB
      | LibraryC
    | Applications
      | ApplicationD
      | ApplicationE

This is a single solution containing both shared class libraries and multiple applications. Currently references to the class libraries by the applications are local in-solution references.

What I would like to do is to publish the libraries (A,B,C) as versioned NuGet packages which are then referenced by the applications as needed (D,E). This allows a change to a shared library to be independent from an update to an application which is deployed. Without this, changing one library could cause the binaries to change in a dozen or more applications, all of which would technically need to be tested. This is undesirable, and versioning with NuGet fixes this.

However, let us say that I want to update the content of LibraryA and ApplicationD at the same time. In order to do this after we have switched to NuGet, I will have to make changes to LibraryA, commit them, wait for the package to be created, tell ApplicationD to update its reference to LibraryA, and then test or develop in ApplicationD. This is far more complicated than simply working with both at the same time using local in-solution references.

What is a better way to get both the robustness of versioned NuGet packages for my shared class libraries while also keeping development simple even if it spans over multiple projects and applications? The only other solutions I have found all involve too much overhead or headache, such as having to constantly change the references for ApplicationD between the NuGet package and the local project.

**EDIT:** To clarify the premise, this question assumes the following:

 - The architecture (solution and project organization) cannot be significantly reorganized
 - Shared libraries are going to change at a non-trivial frequency
 - Changing a shared library cannot force any application to be updated
 - Applications can reference different versions of shared libraries

Pain-free local development while also referencing NuGet packages

I have installed VisualStudio 2013 Community, as per Microsoft documentation [VisualStudio 2013 Community][1] is free and will not require any license. 

But today I saw a notification on VisualStudio 2013 community IDE prompting me to update the trial license. Is this a bug?


  [1]: https://www.visualstudio.com/en-us/news/vs2013-community-vs.aspx

VisualStudio Community 2013 prompts to update trial license

One way to get cmake to build x86 on Windows with Visual Studio is like so:

 1. Start Visual Studio Command prompt for x86
 2. Run cmake: `cmake -G &quot;NMake Makefiles&quot; \path_to_source\`
 3. nmake

One way to get cmake to build x64 on Windows with Visual Studio is like so:

 1. Start Visual Studio Command prompt for x64
 2. Run cmake: `cmake -G &quot;NMake Makefiles&quot; \path_to_source\`
 3. nmake

Using Cmake, how do I compile either or both architectures? (like how Visual Studio does it from in the IDE)



How to build x86 and/or x64 on Windows from command line with CMAKE?

I have 2 folders &quot;inc&quot; and &quot;lib&quot; in my project which have headers and static libs respectively. How do I tell cmake to use those 2 directories for include and linking respectively?

How do I add a library path in cmake?

I have the following setup for C++ development:

- `OS X Yosemite`
- `CLion 140.2310.6` (a cross-plattform C/C++-IDE by JetBrains using `CMake` as build system)
- installed `boost` via `brew install boost` into `/usr/local/Cellar/boost/`

Now, my goal is to setup a simple project and include the `boost` library. I defined just one **test.cpp** file that looks like this:

    #include &lt;iostream&gt;
    #include &lt;boost&gt;
    
    using namespace std;
    
    int test() {
        cout &lt;&lt; &quot;Hello, World!&quot; &lt;&lt; endl;
        return 0; 
    }

My **CMakeLists.txt** file looks like this:

    cmake_minimum_required(VERSION 2.8.4) 
    project(MyProject)
    
    set(CMAKE_CXX_FLAGS &quot;${CMAKE_CXX_FLAGS} -std=c++11&quot;) 
    
    include_directories(&quot;/usr/local/Cellar/boost/1.57.0/include/boost&quot;)
    
    set(SOURCE_FILES main.cpp ./test.cpp)
    add_executable(MyProject ${SOURCE_FILES}) 

When I build the project, I get the following error:


&gt; /Users/nburk/Documents/uni/master/master_thesis/MyProject/test.cpp:2:10:
&gt; fatal error: &#39;boost&#39; file not found

&gt; make[3]: \*** [CMakeFiles/MyProject.dir/test.cpp.o] Error 1 
&gt; make[2]: \*** [CMakeFiles/MyProject.dir/all] Error 2 
&gt; make[1]: \*** [CMakeFiles/MyProject.dir/rule] Error 2 
&gt; make: \*** [MyProject] Error 2

I played around with adjusting paths here and there and also using `add_library` and `target_link_libraries`, none of which made the project build successfully. 

**Can someone point into the right direction how to make sure I can include `boost`s functionality into my CLion C++ project?**

**Update:**
Thanks to @Waxo&#39;s answer I used the following code in my **CMakeLists.txt** file which:

    set(Boost_INCLUDE_DIR /usr/local/Cellar/boost/1.57.0)
    set(Boost_LIBRARY_DIR /usr/local/Cellar/boost/1.57.0/lib)
    find_package(Boost COMPONENTS system filesystem REQUIRED)
    include_directories(${Boost_INCLUDE_DIR})

I now got past the **file not found**-error, but instead I get the following:

&gt; CMake Error at /Applications/CLion
&gt; EAP.app/Contents/bin/cmake/share/cmake-3.1/Modules/FindBoost.cmake:685
&gt; (file):   
&gt; 
&gt;    file STRINGS file &quot;/usr/local/Cellar/boost/1.57.0/boost/version.hpp&quot; cannot   be read.
&gt; 
&gt;    Call Stack (most recent call first):   CMakeLists.txt:11
&gt; (find_package)

Any ideas what I am still missing? The referred line (685) in **FindBoost.cmake** is:
` file(STRINGS &quot;${Boost_INCLUDE_DIR}/boost/version.hpp&quot; _boost_VERSION_HPP_CONTENTS REGEX &quot;#define BOOST_(LIB_)?VERSION &quot;)`


How to include external library (boost) into CLion C++ project with CMake?

Looking around on the net I have seen a lot of code like this:

```cmake
include(FindPkgConfig)
pkg_search_module(SDL2 REQUIRED sdl2)

target_include_directories(app SYSTEM PUBLIC ${SDL2_INCLUDE_DIRS})
target_link_libraries(app ${SDL2_LIBRARIES})
```

However that seems to be the wrong way about doing it, as it only uses the include directories and libraries, but ignored defines, library paths and other flags that might be returned by `pkg-config`.

What would be the correct way to do this and ensure that all compile and link flags returned by `pkg-config` are used by the compiled `app`? And is there a single command to accomplish this, i.e. something like `target_use(app SDL2)`?

ref:
  
* [`include()`](https://cmake.org/cmake/help/latest/command/include.html)  
* [`FindPkgConfig`](https://cmake.org/cmake/help/latest/module/FindPkgConfig.html)

What is the proper way to use `pkg-config` from `cmake`?

I feel almost silly for asking this but I couldn&#39;t find anything on this...

Suppose I have a `cmake` project containing a number of targets (libraries, executables, external targets, etc).  How do I list them using the `cmake` command line interface?

I want a list of things that are valid to substitute for `$target` in the following command line:

    cmake . &amp;&amp; cmake --build . --target $target

**Lot&#39;s** of bonus points for a solution that uses neither `grep` nor `find` nor `python` nor `perl` nor... you get the idea.

Content Type	Original Author	Original Content on Stackoverflow
Question	sashoalm	View Question on Stackoverflow
Solution 1 - C++	sashoalm	View Answer on Stackoverflow
Solution 2 - C++	user2902980	View Answer on Stackoverflow

What are ALL_BUILD and ZERO_CHECK and do I need them?

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Android Studio : emulator is already running

How do I install requirements in Go? "cannot find package"

Attributions