Question

Is there a way to have some kind of default constructor (like a C++ one) for C user types defined with a structure?

I already have a macro which works like a fast initializer (like the one for pthread_mutex) but I wanted to know if you can by any chance have some (or all) fields of a struct filled at declaration.

For instance, with the pthread_mutex example, I would like

pthread_mutex_t my_mutex; 

to have the same effect as

pthread_mutex_t my_mutex = PTHREAD_MUTEX_INITIALIZER; 

Answer 1

You can create initializer functions that take a pointer to a structure. This was common practice.

Also functions that create a struct and initialize it (like a factory) – so there is never a time where the struct is ‘uninitialized’ in the ‘client’ code. Of course – that assumes people follow the convention and use the ‘constructor’/factory…

horrible pseudo code with NO error checking on malloc or free

somestruct* somestruct_factory(/* per haps some initializer agrs? */) {   malloc some stuff   fill in some stuff   return pointer to malloced stuff }   void somestruct_destructor(somestruct*) {   do cleanup stuff and also free pointer   free(somestruct); } 

Someone will probably come along and explain how some early C++ preprocessors/compilers worked to do this all in C.