typedef decalrations

[Andrew Chalk]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

Thanks!

 

[Ivan Vecerina]

| I can:
|
| typedef char D1;
|
| why can't I:
|
| typedef char[1400] D2;
|
| I.e. declare a typedef corresponding to 1400 bytes.

You can, but you have to write it as follows:
typedef char D2[1400];

Remember that the expression that follows typedef should
always follow the same syntax as a variable declaration.


Note: for quick answers to simple problems, posting
to comp.lang.c++ (without cross-posting to the
*.moderated one) will provide you with faster
responses...

hth

 

[Russell Hanneken]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

You can, but you have to write it like this:

typedef char D2[1400];

Regards,

Russell Hanneken
(e-mail address removed)

 

[Attila Feher]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

You can:

typedef char D2[1400];

Just like a variable declaration.

 

[Ivan Vecerina]

| I can:
|
| typedef char D1;
|
| why can't I:
|
| typedef char[1400] D2;
|
| I.e. declare a typedef corresponding to 1400 bytes.

You can, but you have to write it as follows:
typedef char D2[1400];

Remember that the expression that follows typedef should
always follow the same syntax as a variable declaration.


hth

 

[Gabriel Dos Reis]

| why can't I:
|
| typedef char[1400] D2;

try

typedef char D2[1400];

 

[Ben Hutchings]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

That isn't normal declarator syntax. You wouldn't declare an
object D2 as:

char[1400] D2;

but instead as:

char D2[1400];

With minor exceptions, typedef statements use the same
declarator syntax as object and function declarations, so you
should write:

typedef char D2[1400];

 

[Dhruv]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

It can, just place the array thing after D2. So, it would change to
something like:

typedef char D2[1400];

Would make D2 an array of 1400 chars, so using it like this would mean
using an array of chars.

D2 DObj;


Be careful of 1 thing though. If you use new to create a new D2 object,
be sure to delete[] it, and not delete it.


Regards,
-Dhruv.

 

[Marco Manfredini]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

try:
typedef char D2[14000];

Syntactically, a typedef works like a variable declaration, only that
you are declaring a type instead a variable.

Marco

 

[Dan McLeran]

I can:

typedef char D1;

why can't I:

typedef char[1400] D2;

I.e. declare a typedef corresponding to 1400 bytes.

Thanks!

D2 doesn't make much sense. What you're doing is creating an alias for
a type, not assigning a size, i.e. you would write:

char buffer[1400], not char[1400] buffer.

What you can do is something like this:

template<unsigned size>
struct wrapper
{
char buffer[size];
};

typedef wrapper<1400> t2;

int main()
{
return 0;
}

 

[Francis Glassborow]

D2 doesn't make much sense. What you're doing is creating an alias for
a type, not assigning a size, i.e. you would write:

char buffer[1400], not char[1400] buffer.

What you can do is something like this:

template<unsigned size>
struct wrapper
{
char buffer[size];
};

typedef wrapper<1400> t2;

int main()
{
return 0;
}

But why not use the simple answer of writing the original declaration
correctly:

typedef char D2[1400];

? There is no point in reaching for a Swiss-army knife because you hit
your thumb with a hammer instead of the nail.

 

[Attila Feher]

Francis Glassborow wrote:
[SNIP]

But why not use the simple answer of writing the original declaration
correctly:

typedef char D2[1400];

Like I did! I am a good boy.

? There is no point in reaching for a Swiss-army knife because you hit
your thumb with a hammer instead of the nail.

Hm. Why would I want to hit my thumb with a nail?