Yes. The casts are redundant. In your expression:

    true == 1

Integral promotion applies and the bool value will be promoted to an `int` and this promotion must yield 1.

Reference:  4.7 [conv.integral] / 4: If the source type is `bool`... `true` is converted to one.

Charles Bailey&#39;s answer is correct. The exact wording from the C++ standard is (&#167;4.7/4): &quot;If the source type is bool, the value false is converted to zero and the value true is converted to one.&quot; 

Edit: I see he&#39;s added the reference as well -- I&#39;ll delete this shortly, if I don&#39;t get distracted and forget...

Edit2: Then again, it is probably worth noting that while the Boolean values themselves always convert to zero or one, a number of functions (especially from the C standard library) return values that are &quot;basically Boolean&quot;, but represented as `int`s that are normally only required to be zero to indicate false or non-zero to indicate true. For example, the is* functions in `&lt;ctype.h&gt;` only require zero or non-zero, not necessarily zero or one.

If you cast that to `bool`, zero will convert to false, and non-zero to true (as you&#39;d expect).

According to the standard, you should be safe with that assumption. The C++ `bool` type has two values - `true` and `false` with corresponding values 1 and 0.

The thing to watch about for is mixing `bool` expressions and variables with `BOOL` expression and variables. The latter is defined as `FALSE = 0` and `TRUE != FALSE`, which quite often in practice means that any value different from 0 is considered `TRUE`.

A lot of modern compilers will actually issue a warning for any code that implicitly tries to cast from `BOOL` to `bool` if the `BOOL` value is different than 0 or 1.

I&#39;ve found different compilers return different results on true.  I&#39;ve also found that one is almost always better off comparing a bool to a bool instead of an int.  Those ints tend to change value over time as your program evolves and if you assume true as 1, you can get bitten by an unrelated change elsewhere in your code.

If I write the code:

```      
int a=true;
cout&lt;&lt;a;
```

The output will be:

```
1
```

So yes, you can assume `(bool)true==(int)1`

How can I add a trailing slash (`/` for *nix, `\` for win32) to a directory string, if the tailing slash is not already there? Thanks!

Python, add trailing slash to directory string, os independently

I know I can put escaped HTML tags in string resources. However, looking at the source code for the Contacts application I can see that they have a way of not having to encode the HTML. Quote from the Contacts application [strings.xml](http://android.git.kernel.org/?p=platform/packages/apps/Contacts.git;a=blob;f=res/values/strings.xml;h=e37c1182741baf957fa47c3b2fc345be86b659c1;hb=HEAD):

    &lt;string name=&quot;contactsSyncPlug&quot;&gt;&lt;font fgcolor=&quot;#ffffffff&quot;&gt;Sync your Google contacts!&lt;/font&gt; 
    \nAfter syncing to your phone, your contacts will be available to you wherever you go.&lt;/string&gt;

Unfortunately, when I try something similar (like `Hello, &lt;b&gt;World&lt;/b&gt;!`), `getString()` returns the string without the tags (I can see that in `logcat`). Why is that? How can I get the original string, with tags and everything? How is the Contacts application doing it?

HTML in string resource?

Can I assume `(bool)true == (int)1` for any C++ compiler ?

Can I assume (bool)true == (int)1 for any C++ compiler?

<p>Can I assume <code>(bool)true == (int)1</code> for any C++ compiler ?</p>


I&#39;m compiling a c++ program using `g++` and `ld`. I have a `.so` library I want to be used during linking. However, a library of the same name exists in `/usr/local/lib`, and `ld` is choosing that library over the one I&#39;m directly specifying. How can I fix this?


For the examples below, my library file is `/my/dir/libfoo.so.0`. Things I&#39;ve tried that don&#39;t work:

- my g++ command is `g++ -g -Wall -o my_binary -L/my/dir -lfoo bar.cpp`
- adding `/my/dir` to the beginning or end of my `$PATH` en` variable
- adding `/my/dir/libfoo.so.0` as an argument to g++

How to specify preference of library path?

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

The ISO C Standard (ISO/IEC 9899) and the ISO C++ Standard (ISO/IEC 14882) are not published online; instead, one must purchase the PDF for each of those standards. I am wondering what the rationale is behind this... is it not detrimental to both the C and C++ programming languages that the authoritative specification for these languages is not made freely available and searchable online? Doesn&#39;t this encourage the use of possibly inaccurate, non-authoritative sources for information regarding these languages?

While I understand that much time and effort has gone into developing the C and C++ standards, I am still somewhat puzzled by the choice to charge for the specification. The &lt;a href=&quot;http://www.opengroup.org/onlinepubs/009695399/&quot;&gt;OpenGroup Base Specification&lt;/a&gt;, for example, is available for free online; they make money by charging for certification. Does anyone know why the ISO standards committees don&#39;t make their revenue in certifying standards compliance, instead of charging for these documents? Also, does anyone know if the ISO standards committee&#39;s &lt;a href=&quot;http://www.open-std.org/jtc1/sc22/wg21/&quot;&gt;atrociously looking website&lt;/a&gt; is intentionally made to look that way? It&#39;s as if they don&#39;t want people visiting and buying the spec.

One last thing... the C and C++ standards are generally described as &quot;open standards&quot;... while I realize that this means that anyone is permitted to implement the standard, should that definition of &quot;open&quot; be revised? Charging for the standard rather than making it openly available seems contrary to the spirit of openness.

P.S.  I do have a copy of the ISO/IEC 9899:1999 and ISO/IEC 14882:2003, so please no remarks about being cheap or anything... although if you are tempted to say such things, you might want to consider the high school, undergraduate, and graduate students who might not have all that much extra cash. Also, you might want to consider the fact that the ISO website is really sketchy and they don&#39;t even tell you the cost until you proceed to the checkout... doesn&#39;t really encourage one to go and get a copy, now does it?

&lt;b&gt;Edit / Comment&lt;/b&gt;&lt;br /&gt;
It occurs to me that if the ISO standards committees were to make their revenues from certification that it would incentivize smaller but more frequent changes to the standard rather than very large revisions very infrequently. It would also incentivize creating an implementable standard (I doubt the ISO C++ committee would have introduced &quot;export&quot; in the first place if they got their revenues from certification).

I have found a solution to one of the annoyances of not having the PDF online.... I have uploaded my copy of the standards into my Google Docs, so that I can still access it from any computer without carrying it around.

ISO/IEC Website and Charging for C and C++ Standards

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?

Given integer values `x` and `y`, C and C++ both return as the quotient `q = x/y` the floor of the floating point equivalent.  I&#39;m interested in a method of returning the ceiling instead.  For example, `ceil(10/5)=2` and `ceil(11/5)=3`.

The obvious approach involves something like:

    q = x / y;
    if (q * y &lt; x) ++q;

This requires an extra comparison and multiplication; and other methods I&#39;ve seen (used in fact) involve casting as a `float` or `double`.  Is there a more direct method that avoids the additional multiplication (or a second division) and branch, and that also avoids casting as a floating point number?

Fast ceiling of an integer division in C / C++

I know you can convert a `String` to an number with `read`:

    Prelude&gt; read &quot;3&quot; :: Int
    3
    Prelude&gt; read &quot;3&quot; :: Double 
    3.0

But how do you grab the `String` representation of an `Int` value?

Haskell: Converting Int to String

While trying to learn [Unity][1], I keep seeing the following code for overriding `GetControllerInstance` in MVC:

    if(!typeof(IController).IsAssignableFrom(controllerType)) { ... }

this seems to me a pretty convoluted way of basically writing

    if(controllerType is IController) { ... }

I appreciate there are subtle differences between `is` and `IsAssignableFrom`, ie `IsAssignableFrom` doesn&#39;t include cast conversions, but I&#39;m struggling to understand the implication of this difference in practical scenarios.

When is it imporantant to choose `IsAssignableFrom` over `is`? What difference would it make in the `GetControllerExample`?

    if (!typeof(IController).IsAssignableFrom(controllerType))
          throw new ArgumentException(...);
    return _container.Resolve(controllerType) as IController;
                


  [1]: http://weblogs.asp.net/shijuvarghese/archive/2010/05/07/dependency-injection-in-asp-net-mvc-nerddinner-app-using-unity-2-0.aspx

Use of IsAssignableFrom and &quot;is&quot; keyword in C#

For this code block:

    int num = 5;
    int denom = 7;
    double d = num / denom;

the value of `d` is `0.0`. It can be forced to work by casting:

    double d = ((double) num) / denom;

But is there another way to get the correct `double` result? I don&#39;t like casting primitives, who knows what may happen.

Integer division: How do you produce a double?

Eric Lippert&#39;s comments in [this question](https://stackoverflow.com/questions/3166349/what-is-the-type-in-typeobjectname-var) have left me thoroughly confused. What is the difference between casting and conversion in C#?

What is the difference between casting and conversion?

I am curious to know what the difference is between a cast to say an `int` compared to using `Convert.ToInt32()`. Is there some sort of performance gain with using one?

Also which situations should each be used for? Currently I&#39;m more inclined to use `Convert` but I don&#39;t have a reason to go either way. In my mind I see them both accomplishing the same goal.

When to use a Cast or Convert

Is it guaranteed that `False == 0` and `True == 1`, in Python (assuming that they are not reassigned by the user)?  For instance, is it in any way guaranteed that the following code will always produce the same results, whatever the version of Python (both existing and, likely, future ones)?

    0 == False  # True
    1 == True   # True
    [&#39;zero&#39;, &#39;one&#39;][False]  # is &#39;zero&#39;

Any reference to the official documentation would be much appreciated!

**Edit**: As noted in many answers, `bool` inherits from `int`.  The question can therefore be recast as: &quot;Does the documentation officially say that programmers can rely on booleans inheriting from integers, *with the values `0` and `1`*?&quot;.  This question is relevant for writing robust code that won&#39;t fail because of implementation details!

Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?

What is the default value of a `BOOL` variable in Objective-C?

Default value of BOOL

    false; echo $?

The above will output `1`, which is contradictory with all other programming languages I know.

Any reason in this?

Why 0 is true but false is 1 in the shell?

I have set up one of my core data attributes as a Boolean.  Now, I need to set it, but XCode keeps telling me that it may not respond to setUseGPS.

    [ride setUseGPS: useGPS.on];

What is the method for setting a boolean in core data?  All my other attributes are set this way, and they work great.  So, not sure why a boolean does not work to be set this way?

iPhone: Save boolean into Core Data

I tried to declare a Boolean variable in a shell script using the following syntax:

    variable=$false

    variable=$true

Is this correct? Also, if I wanted to update that variable would I use the same syntax? Finally, is the following syntax for using Boolean variables as expressions correct?

    if [ $variable ]

    if [ !$variable ]


Content Type	Original Author	Original Content on Stackoverflow
Question	Petruza	View Question on Stackoverflow
Solution 1 - C++	CB Bailey	View Answer on Stackoverflow
Solution 2 - C++	Jerry Coffin	View Answer on Stackoverflow
Solution 3 - C++	Franci Penov	View Answer on Stackoverflow
Solution 4 - C++	Michael Dorgan	View Answer on Stackoverflow
Solution 5 - C++	Anwesha Roy	View Answer on Stackoverflow

Can I assume (bool)true == (int)1 for any C++ compiler?

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Solution 3 - C++

Solution 4 - C++

Solution 5 - C++

HTML in string resource?

Python, add trailing slash to directory string, os independently

Attributions