Standard typedefs ...

[twomers]

Hi, why do people use certain typedefs for different things? like I think I saw one for "int" and stuff. I can understand one for "unsigned double long float character" (i made that one up by the way), and perhaps for BOOL, TRUE & FALSE, but .... yeah, I just found it odd is all.

so anyone know why?

[jwenting]

to make C look like something they are comfortable with.
I've come across the following more than once:

#define begin {
#define end }
#define integer int
#define real float
#define procedure void
// etc...

which would lead to something like

procedure doSomething(integer a)
begin
  real b;
  // do something more
end

which would look familiar to Pascal or Modula programmers.

[ammar]

It's for added flexibilty...
This way writing the code would become easier to you.

This is why C is such a nice language

[Salem]

> to make C look like something they are comfortable with.
I'm sure you jest, but ugh!!!!!
http://c-faq.com/cpp/slm.html

> Hi, why do people use certain typedefs for different things?
Readability is one issue - function pointers in particular are unweildy beasts otherwise.

Portability, say you have
typedef int colour_t;
Which on another system you have to do
typedef unsigned long colour_t;

If you'd used colour_t properly, this would be a much easier change than hunting down every int, and deciding whether it needed changing to unsigned long.

Also, typedefs can do things which #defines can't.

[nvoigt]

Example from my desk: We have a client-server system that executes batch jobs. Each job can have a number of steps, each step processes records, each record processed has a return code. Since the system was developed, this code has always been an int. Batch functions return ints, the servers handle ints, statistic modules work with the ints, databases store the ints... until recently, we added a feature and found that ints were not enough. We needed 64-bit numbers.

If we had properly typedef'd it like this

typedef int RECORD_RETURN_CODE;

We would have been in heaven.

typedef __int64 RECORD_RETURN_CODE;

One little change, maybe adjust the database and some minor display issues... done.

Instead we had to go through every single function and look at every single int and check if it was an int or maybe the returncode of one of those functions.

[jwenting]

> to make C look like something they are comfortable with.
I'm sure you jest, but ugh!!!!!

sadly I'm not

[JaWiB]

Heh, it's the Secret to Better C