Question

I have noticed that Doxygen can link member functions calls from instances, when the default constructor takes no arguments, but fails to link them, when the constructor takes arguments.

• Why is that?
• Is there a workaround to manually add links within a @code/@endcode block?

In the example below:

• t.foo() – foo() is linked
• u.foo() – foo() is not linked

.

/** @file doxy.cpp */

/** struct T */
struct T {
  /** foo */
  void foo() { }
};

/** struct U */
struct U {
  int a; /**< int a */

  /** U */
  U(int a_) : a(a_) { }

  /** foo */
  void foo() { }
};

/**
 * main
 *
 * @code
 * T t;
 * t.foo();  // foo is linked
 *
 * U u(42);
 * u.foo();  // foo is not linked
 * @endcode
 */
int main()
{
  return 0;
}

Answer 1

I think this is a symptom of a known issue in Doxygen. From http://www.doxygen.nl/manual/trouble.html

Redundant braces can confuse doxygen in some cases. For example:

void f (int); 

is properly parsed as a function declaration, but

const int (a);

is also seen as a function declaration with name int,
because only the syntax is analyzed, not the semantics. If the
redundant braces can be detected, as in

int *(a[20]); 

then doxygen will remove the braces and correctly parse the result.

So in this case, I believe:

U u(42);

is being interpreted as a function instead of as a variable declaration.

Unfortunately, I’m not aware of any options for explicitly adding links within a code block. The only workaround I’ve found is to restructure the code so that the declaration doesn’t look like a function to Doxygen. For example, changing your variable initialization to this:

U u = U(42);

allows Doxygen to recognize u as a variable instead of a function.