Is wrapping STL idioms for readability a good idea?

Asked 2010-07-29T17:27:15.950

I'm currently working on a C++ project that needs to have as few external dependencies as possible, and thus I'm pretty much sticking to STL and Boost. Until now, I've been almost exclusively living in Qt-land when it comes to C++. In general I tend to use C# and Python when I can.

Today I wanted to check whether a std::vector contained a certain item. With Qt, I'd do this like so:

QList< int > list;
list.append( 1 );
list.append( 2 );
list.append( 3 );

if ( list.contains( 2 ) )
{
    // do something
}

Nice and readable. But std::vector has no contains method, which was a surprise. Ok... what would the STL idiom for something like that be? Searching around, it seems to be this:

std::vector< int > list;
list.push_back( 1 );
list.push_back( 2 );
list.push_back( 3 );

std::vector< int >::const_iterator result =
    std::find( list.begin(), list.end(), 2 );

if ( result != list.end() )
{
    // do something
}

That (to me) is hardly readable and much too verbose. So I found myself writing a utility function that takes a vector and a value and returns bool depending on whether the value was found or not. Basically, a templated contains() method; a wrapper for the above std::find call. I can then use that in a way that is similar to the Qt example.

I have several similar utility functions in mind that would wrap other STL idioms for no other reason but a (perceived) increase in readability. What I want to know is... is this a bad idea? Do other people do the same? Am I missing something crucial? The code will be OSS at one point, and I'd rather not do something idiosyncratic that other C++ devs would find strange.

c++ stl readability

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2 Answers

There is nothing wrong in writing the utility functions that will help you and will make your code cleaner. Other people do the same. Boost library is the biggest set of such utility functions and classes.

More to say C++ Standard explicitly proposes to extend the Standard Library (17.3.1.2/1):

The library can be extended by a C++ program. Each clause, as applicable, describes the requirements that such extensions must meet. Such extensions are generally one of the following:

Template arguments

Derived classes

Containers, iterators, and/or algorithms that meet an interface convention

answered 2010-07-29T17:34:59.820

I'd say it's definitely a good idea. The C++ STL is missing a lot of what Python/C# programmers have come to expect from a standard library. If you can make your code more readable by taking that 2-3 line STL approach and making it a single function, go ahead!

Here's another example of a very similar issue: I often want to convert an int to a std::string. To my surprise, there's no concise way of doing this using the STL. So, I wrote a toStr function that runs the 2-3 lines required to put an int into a stringstream and return the resulting string.

Edit: To clarify, I recommend looking for boost solutions before creating your own. My example was intended to demonstrate the limitations of the STL, but has the alternative interpretation of, "whatever the STL is missing, boost has."

answered 2010-07-29T17:40:56.263

Is wrapping STL idioms for readability a good idea?

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