Only use this method around a block of headers that you cannot change, but that you need to include. 

You can selectively, and temporarily disable all warnings like this:

    #pragma warning(push, 0)        
    //Some includes with unfixable warnings
    #pragma warning(pop)

Instead of 0 you can optionally pass in the warning number to disable, so something like:

    #pragma warning( push )
    #pragma warning( disable : 4081)
    #pragma warning( disable : 4706 )
    // Some code
    #pragma warning( pop ) 

Visual C++ team has just added support for warning levels in external headers. You can find the details in their blog post: [Broken Warnings Theory][1].

In essence it does automatically what the suggestions here were recommending to do manually: pushes new warning level right before #include directive and pops it up right after. There are additional flags to specify locations of external headers, flag to treat all &lt;&gt; includes as external, #pragma system_header and a feature not available in Clang or GCC (as of this writing) to see warnings in external headers across template instantiation stack when the template was instantiated in the user code.

Besides the comments under that post, you can also find some useful discussion in [a reddit announcement for that post][2].


  [1]: https://blogs.msdn.microsoft.com/vcblog/2017/12/13/broken-warnings-theory/
  [2]: https://www.reddit.com/r/cpp/comments/7jnw4r/broken_warnings_theory/

I don&#39;t believe Visual C++ lets you differentiate. You can fake it by using &lt;code&gt;#pragma warning&lt;/code&gt; around the include:

    #pragma warning(push, 0)
    #include &quot;mywarningheader.h&quot;
    #pragma warning(pop)



It seems like there is an answer to this.

[this post][1] talks about `/external:I` that can be used to include headers with a special set of warnings.

I have not tested it myself, but the blog post is from 2017.


  [1]: https://devblogs.microsoft.com/cppblog/broken-warnings-theory/

Given a string `s`, what is the fastest method to generate a set of all its unique substrings?

Example: for `str = &quot;aba&quot;` we would get `substrs={&quot;a&quot;, &quot;b&quot;, &quot;ab&quot;, &quot;ba&quot;, &quot;aba&quot;}`.

The naive algorithm would be to traverse the entire string generating substrings in length `1..n` in each iteration, yielding an `O(n^2)` upper bound.

Is a better bound possible?

*(this is technically homework, so pointers-only are welcome as well)*

Generate all unique substrings for given string

Just wondering in php, if it was possible to convert a string to a double. I am using a financial web service which provides a price as a string. I really need to process this as a double and was wondering how i would convert it

thanks

Convert a string to a double - is this possible?

I&#39;m starting a new BREW project, and I&#39;d like to compile with Warning Level 4 (/W4) to keep the application code nice and clean. The problem is that the BREW headers themselves don&#39;t compile cleanly with /W4.

In gcc you can differentiate between application and system headers by using -I and -isystem, and then by default gcc doesn&#39;t report any compilation warnings in system headers. Is there an equivalent mechanism in Visual C++?

How to suppress warnings in external headers in Visual C++

<p>I'm starting a new BREW project, and I'd like to compile with Warning Level 4 (/W4) to keep the application code nice and clean. The problem is that the BREW headers themselves don't compile cleanly with /W4.</p>
<p>In gcc you can differentiate between application and system headers by using -I and -isystem, and then by default gcc doesn't report any compilation warnings in system headers. Is there an equivalent mechanism in Visual C++?</p>


This is a feature I have grown accustomed to in Eclipse (&lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;Tab&lt;/kbd&gt;). Is there an equivalent in Visual C++?

Is there a shortcut to move between header and source file in VC++?

I am trying to find out the version of Visual Studio that is used to compile the Python on my computer

It says 

&lt;!-- language: lang-none --&gt;

    Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02) [MSC v.1500 32 bit (Intel)] on win32

What I do not understand is this `MSC V.1500` designation. Does it mean it is compiled with Visual Studio 2005? I cannot find this information on http://python.org.

What version of Visual Studio is Python on my computer compiled with?

error LNK2005: xxx already defined in MSVCRT.lib(MSVCR100.dll)	C:\something\LIBCMT.lib(setlocal.obj)

I know this.

**Calling C function from C++:**

If my application was in C++ and I had to call functions from a library written in C. Then I would have used 

    //main.cpp
    
    extern &quot;C&quot; void C_library_function(int x, int y);//prototype
    C_library_function(2,4);// directly using it.

This wouldn&#39;t mangle the name `C_library_function` and linker would find the same name in its input *.lib files and problem is solved.

**Calling C++ function from C???**

But here I&#39;m extending a large application which is written in C and I need to use a library which is written in C++. Name mangling of C++ is causing trouble here. Linker is complaining about the unresolved symbols. Well I cannot use C++ compiler over my C project because thats breaking lot of other stuff. What is the way out?

By the way I&#39;m using MSVC

How to call C++ function from C?

I compiled my bison-generated files in Visual Studio and got these errors:

&gt; ...\position.hh(83): error C2589: &#39;(&#39; : illegal token on right side of &#39;::&#39;  
&gt; ...\position.hh(83): error C2059: syntax error : &#39;::&#39;  
&gt; ...\position.hh(83): error C2589: &#39;(&#39; : illegal token on right side of &#39;::&#39;  
&gt; ...\position.hh(83): error C2059: syntax error : &#39;::&#39;

The corresponding code is:

    inline void columns (int count = 1)
    {
      column = std::max (1u, column + count);
    }

I think the problem is with std::max; if I change std::max to equivalent code then there is no problem anymore, but is there a better solution instead of changing the generated code?

Here is the bison file I wrote:

    //
    // bison.yy
    //
    
    %skeleton &quot;lalr1.cc&quot;
    %require &quot;2.4.2&quot;
    %defines
    %define parser_class_name &quot;cmd_parser&quot;
    %locations
    %debug
    %error-verbose
    
    %code requires {
    class ParserDriver;
    }
    
    %parse-param { ParserDriver&amp; driver }
    %lex-param { ParserDriver&amp; driver }
    
    %union {
        struct ast *a;
        double d;
        struct symbol *s;   
        struct symlist *sl;
        int fn;         
    }
    
    %code {
    #include &quot;helper_func.h&quot;
    #include &quot;ParserDriver.h&quot;
    std::string error_msg = &quot;&quot;;
    }
    
    %token &lt;d&gt; NUMBER
    %token &lt;s&gt; NAME
    %token &lt;fn&gt; FUNC
    %token EOL
    %token IF THEN ELSE WHILE DO LET
    %token SYM_TABLE_OVERFLOW
    %token UNKNOWN_CHARACTER
    
    %nonassoc &lt;fn&gt; CMP
    %right &#39;=&#39;
    %left &#39;+&#39; &#39;-&#39;
    %left &#39;*&#39; &#39;/&#39;
    %nonassoc &#39;|&#39; UMINUS
    
    %type &lt;a&gt; exp stmt list explist
    %type &lt;sl&gt; symlist
    
    %{
    extern int yylex(yy::cmd_parser::semantic_type *yylval,
     yy::cmd_parser::location_type* yylloc);
    %}
    
    %start calclist
    %%
    
    ... grammar rules ...



Problem calling std::max

I have a super class like this:

    class Parent
    {
    public:
        virtual void Function(int param);
    };
    
    void Parent::Function(int param)
    {
        std::cout &lt;&lt; param &lt;&lt; std::endl;
    }

..and a sub-class like this:

    class Child : public Parent
    {
    public:
        void Function(int param);
    };
    
    void Child::Function(int param)
    {
        ;//Do nothing
    }

When I compile the sub-class .cpp file, I get this error

    warning C4100: &#39;param&#39; : unreferenced formal parameter

As a practice, we used to treat warnings as errors. How to avoid the above warning?

Thanks.

Avoid warning &#39;Unreferenced Formal Parameter&#39;

Or preferably all of them instead of just my code? My program uses Gtk, Loudmouth and few other things, and these two (and some behind them, libgcrypto, libssl) are causing so many errors themselves that I&#39;m unable to detect my own. Is it possible to make valgrind ignore things coming from deeper than my own code?

Is it possible to make valgrind ignore certain libraries?

I was wondering if scala had an equivalent to java&#39;s [@SuppressWarnings](http://download.oracle.com/javase/1.5.0/docs/api/java/lang/SuppressWarnings.html) that can be applied to a function or whatever to ignore any deprecation warnings[1] that function emits?

1: Relevant warning in my case is: `method stop in class Thread is deprecated: see corresponding Javadoc for more information.` I am aware of the problems with stop however there are still some cases where due to legacy code we have to use it.



Is there an equivalent to SuppressWarnings in Scala?

I have a HTTPSystemDefinitions.cs file in C# project which basically describes the older windows ISAPI for consumption by managed code.

This includes the complete set of Structures relevant to the ISAPI not all or which are consumed by code.  On compilation all the field members of these structures are causing a warning like the following:- 

&gt;  Warning	Field &#39;UnionSquare.ISAPI.HTTP_FILTER_PREPROC_HEADERS.SetHeader&#39; is never assigned to, and will always have its default value null

or

&gt;  Warning	The field &#39;UnionSquare.ISAPI.HTTP_FILTER_PREPROC_HEADERS.HttpStatus&#39; is never used

Can these be disabled with `#pragma warning disable`?  If so what would the corresponding error numbers be?  If not is there anything else I can do?  Bear in mind that I only what to do this for this file, its important that I get see warnings like these coming from other files.

__Edit__

Example struct:-

    struct HTTP_FILTER_PREPROC_HEADERS
    {
        //
        //  For SF_NOTIFY_PREPROC_HEADERS, retrieves the specified header value.
        //  Header names should include the trailing &#39;:&#39;.  The special values
        //  &#39;method&#39;, &#39;url&#39; and &#39;version&#39; can be used to retrieve the individual
        //  portions of the request line
        //

        internal GetHeaderDelegate GetHeader;
        internal SetHeaderDelegate SetHeader;
        internal AddHeaderDelegate AddHeader;
            
        UInt32  HttpStatus;               // New in 4.0, status for SEND_RESPONSE
        UInt32  dwReserved;               // New in 4.0
    }

Suppressing &quot;is never used&quot; and &quot;is never assigned to&quot; warnings in C#

I am using Paramiko in my python code (for sftp). Everything works fine except that everytime I import or call a paramiko function. This warning would show up:

    C:\Python26\lib\site-packages\Crypto\Util\randpool.py:40: RandomPool_Deprecation
    Warning: This application uses RandomPool, which is BROKEN in older releases.  S
    ee http://www.pycrypto.org/randpool-broken
      RandomPool_DeprecationWarning)

I know that this has to do with the fact that Paramiko is using some Deprecated functionalities of PyCrypto. 

My question is, is there a way to suppress this warning programmatically ?
I have tried this:

    warnings.filterwarnings(action=&#39;ignore&#39;, \
    category=DeprecationWarning, module=&#39;paramiko&#39;)

and even this:

    warnings.filterwarnings(action=&#39;ignore&#39;, \
    category=DeprecationWarning, module=&#39;randpool&#39;)

before &#39;import paramiko&#39; statement and before paramiko-specific function calls, but nothing works. This warning keeps showing up no matter what.
If it helps, here&#39;s the code in the third party library that prints the warning:

in randpool.py:

    from Crypto.pct_warnings import RandomPool_DeprecationWarning
    import Crypto.Random
    import warnings
    
    class RandomPool:
        &quot;&quot;&quot;Deprecated.  Use Random.new() instead.
    
        See http://www.pycrypto.org/randpool-broken
        &quot;&quot;&quot;
        def __init__(self, numbytes = 160, cipher=None, hash=None, file=None):
            warnings.warn(&quot;This application uses RandomPool, which is BROKEN in older releases.  See http://www.pycrypto.org/randpool-broken&quot;,
                RandomPool_DeprecationWarning)


If you know a way around this, please help me shut this warning off.

Content Type	Original Author	Original Content on Stackoverflow
Question	Bob Whiteman	View Question on Stackoverflow
Solution 1 - Visual C++	Brian R. Bondy	View Answer on Stackoverflow
Solution 2 - Visual C++	solodon	View Answer on Stackoverflow
Solution 3 - Visual C++	Dan Story	View Answer on Stackoverflow
Solution 4 - Visual C++	Lasersköld	View Answer on Stackoverflow

How to suppress warnings in external headers in Visual C++

Visual C++ Problem Overview

Visual C++ Solutions

Solution 1 - Visual C++

Solution 2 - Visual C++

Solution 3 - Visual C++

Solution 4 - Visual C++

Convert a string to a double - is this possible?

Generate all unique substrings for given string

Attributions