Core C++, 3 of N: Overload Resolution -- Stephan T. Lavavej

By Blog Staff | Jul 24, 2012 07:36 PM | Tags: intermediate advanced

Core C++, 3 of N: Overload Resolution -- Stephan T. Lavavej

Stephan T. Lavavej, aka STL, will take us on a journey of discovery within the exciting world of Core C++. We know lots of folks are either coming back to C++, coming to C++, or have never left C++. This lecture series, in n parts, is for all of you! Only STL can make that work (novice, intermediate, and advanced all bundled together and presented in a way only STL can do).

In Part 3, STL digs into Overload Resolution. A function template can overload non-template functions of the same name. In this scenario, function calls are resolved by first using template argument deduction to instantiate the function template with a unique specialization (STL taught us all about TAD in Part 2). If template argument deduction fails, the other function overloads are considered to resolve the call. These other overloads, also known as the candidate set, include nontemplate functions and other instantiated function templates. If template argument deduction succeeds, then the generated function is compared with the other functions to determine the best match, following the rules for overload resolution. [source]

As STL says: "I walk through why foo(const T&) beats foo(const T *), when given int *. The reason is surprisingly subtle."

Tune in.

Core C++, 2 of N: Template Argument Deduction -- Stephan T. Lavavej

By Blog Staff | Jul 9, 2012 07:35 PM | Tags: advanced

Core C++, 2 of N: Template Argument Deduction -- Stephan T. Lavavej

Stephan T. Lavavej, aka STL, will take us on a journey of discovery within the exciting world of Core C++. We know lots of folks are either coming back to C++, coming to C++, or have never left C++. This lecture series, in n parts, is for all of you! Only STL can make that work (novice, intermediate, and advanced all bundled together and presented in a way only STL can do).

In part 2, STL will teach us all about Template Argument Deduction. Template arguments are deduced when a call is made to a template function, but some or all template arguments are omitted. The compiler will attempt to deduce the intended template arguments. In most cases, this works as expected. If it does not, a compilation error occurs, in which case you should specify the template arguments explicitly. Now, let's see what Stephan has to say about this.

Tune in. Learn.

Core C++, 1 of N: Name Lookup -- Stephan T. Lavavej

By Blog Staff | May 16, 2012 07:30 PM | Tags: intermediate advanced

Core C++, 1 of N: Name Lookup -- Stephan T. Lavavej

Stephan T. Lavavej, aka STL, will take us on a journey of discovery within the exciting world of Core C++. We know lots of folks are either coming back to C++, coming to C++, or have never left C++. This lecture series, in n parts, is for all of you! Only STL can make that work (novice, intermediate, and advanced all bundled together and presented in a way only STL can do).

In the following code, which functions are called? Why? Analyze the implications?

namespace A {
      struct X;
      struct Y;
      void f( int );
      void g( X );
}

namespace B {
       void f( int i ) {
            f( i );   // which f()?
        }
        void g( A::X x ) {
             g( x );   // which g()?
        }
        void h( A::Y y ) {
             h( y );   // which h()?
        }
}

We recommend you watch this entire episode before playing around with Herb's sample above (and don't read the GotW answer, either! That's cheating. Learn from STL. He's an outstanding teacher, as you know).

Tune in. Enjoy. Learn.