struct, typedef, and template

[Ed]

Hi, guys,
In C language manner, we need to put a "struct" token before one
struct variable declaration like following.

<code>
struct Apple
{
float Price;
};

struct Apple apple;
</code>

Sometime, we would use typedef to simplify the usage.

<code>
typedef struct _Apple
{
float Price;
} Apple;

Apple apple;
</code>
Now, when we use this manner in C++, it seems we don't need to add a
typedef for the struct declaration.

<code>
struct Apple
{
float Price;
};

Apple apple;
</code>

Directly using "Apple" to do the declaration is OK in VS compiler and
Intel Compiler.
My question is should I still keep the usage of old struct usage.

Why I ask this question is because of template.
I write a template struct.
template <typename Real>
struct Vector
{
Real x;
Real y;
Real z;
};

Vector<floatvector;

You know that we can not add a typedef to a template struct. So, I am
wondering if this is OK.

Thanks!
Ed.

[Ian Collins]

Ed wrote:

Hi, guys,
In C language manner, we need to put a "struct" token before one
struct variable declaration like following.

<code>
struct Apple
{
float Price;
};

struct Apple apple;
</code>

Now, when we use this manner in C++, it seems we don't need to add a
typedef for the struct declaration.

Correct. In C++, struts and classes are types.

--
Ian Collins.

[Ed]

On Aug 25, 4:45*pm, Ian Collins <[e-mail]:

Ed wrote:

Hi, guys,
In C language manner, we need to put a "struct" token before one
struct variable declaration like following.

<code>
struct Apple
{
* *float Price;
};

struct Apple apple;
</code>

Now, when we use this manner in C++, it seems we don't need to add a
typedef for the struct declaration.

Correct. *In C++, struts and classes are types.

--
Ian Collins.

Is this the rule in C++ standard?

[=?utf-8?Q?David_C=C3=B4me?=]

On Mon, 25 Aug 2008 11:00:37 +0200, Ed <se*****@gmail.comwrote:

On Aug 25, 4:45Â*pm, Ian Collins <[e-mail]:

>Ed wrote:

Hi, guys,
In C language manner, we need to put a "struct" token before one
struct variable declaration like following.

<code>
struct Apple
{
Â* Â*float Price;
};

struct Apple apple;
</code>

Now, when we use this manner in C++, it seems we don't need to add a
typedef for the struct declaration.

Correct. Â*In C++, struts and classes are types.

--
Ian Collins.

Is this the rule in C++ standard?

Yep.

[Rolf Magnus]

Ed wrote:

Directly using "Apple" to do the declaration is OK in VS compiler and
Intel Compiler.

It's standard C++.

My question is should I still keep the usage of old struct usage.

Only for those parts of your code that might need to be used from C code.

Why I ask this question is because of template.
I write a template struct.
template <typename Real>
struct Vector
{
Real x;
Real y;
Real z;
};

Vector<floatvector;

You know that we can not add a typedef to a template struct. So, I am
wondering if this is OK.

Yes.