Re: Asterisk Format Question
On 6/22/2014 5:43 AM, Jorgen Grahn wrote:
On Fri, 2014-06-20, Scott Lurndal wrote:
Paavo Helde <myfirstname@osa.pri.ee> writes:
carlos_c_reyes@brown.edu wrote in
news:e520c9d4-7532-491f-984f-5f5526ec179b@googlegroups.com:
I am a bit confused as to the difference between the following lines
declaring functons:
node* insert (node* p_tree, int key); \ Let's call this function
1. node *search (node* p_tree, int key); \Function 2.
So from my understanding, function 1 is a function that takes a
pointer and an integer as arguments and returns a pointer. Function 2
does something similar in which it takes the same exact arguments.
However, what confuses me is the position of the asterisk. Note that
the asterisk is appended to node (which by the way is a simple struct)
in function 1 but in the function two however it is added to the
beginning of the function name search. Any clarification is much
appreciated!
There is no difference, whitespace is ignored by the compiler.
Some people like to write * next to the variable name as be syntax it
belongs there, cf.
int *a, *b, c;
Other people like to write it next to the type as in their mind it is
part of the type.
Which is goofy, because 'int* a,b;' is not the same as 'int *a, *b;'.
For us (the people who like to write 'Foo* bar;', it's the comma
syntax that's goofy. I know people still use it, but see it as mildly
archaic -- especially since in C++ (and C99) so much is going on
around the declaration apart from just variable declaration.
I never seem to have a need to have a block of variable declarations,
like a grocery list, at the top of my functions.
C people can't seem to shake it off, though...
There is a real-time need for the comma syntax in a declaration. What
if a subroutine sets more than one value when called, like so
...
ErrorCode ec = some_subroutine(args, value1, value2);
And suppose you only need to use value1 and value2 if 'ec' is not a code
for an error
if (ec == ErrorCode::NoError)
{
// use value1 and value2
}
and otherwise they mean nothing. I found quite a few places where I
have done just that. Such a sequence of actions totally justifies the
definition of 'value1' and 'value2' in a single statement using the comma:
SomeType value1, value2;
ErrorCode ec = some_subroutine(args, value1, value2);
if (ec == ErrorCode::NoError)
{
... // use value1 and value2
}
// here 'value1' and 'value2' may be unintialized
// (depending on the actual meaning of 'SomeType'
// and we could let them disappear by wrapping the
// entire fragment in curly braces (to prevent
// accidental use of uninitialized objects)
Given that 'some_subroutine' comes from a 3rd party library and its
interface is set in stone, what other approach would you suggest?
V
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