🚀 go-pugleaf

Valentin Bonnard  <bonnardv@pratique.fr> wrote:
>1) String literals
>~~~~~~~~~~~~~~~~~~
>String literals should be const char* instead of char* (if it is not
>already the case).

Actually they're char[], which in practice is almost always decayed to
char*.  The reason they aren't char const[] is that a lot of existing C
code does things like `char *foo="bar";', because const didn't exist in
K&R C.

In my opinion, C++ code tends to use const correctly much more than C
code does.  (I personally always write const correctness into my C
code, but a lot of people do not, quite apart from the matter of
existing code.)  It would therefore probably not be disastrous to have
string literals have type char const[] in C++, though it would be in
C.  Maybe in the next round of standardisation?

>2) Placement operators
>~~~~~~~~~~~~~~~~~~~~~~
>class Object {
>        void    operator+ // or / or whatever
>                         (Object& result, const Object& b) const;
>        void    operator* (Object& result) const;
>        Object  operator* (const Object& result) const; // old one
>}
>
>should be called respectively by:
>a = b + c;
[...]

GCC has a better syntax for this, using a declaration "return result"
between the parameter list and the function body.  The function has a
return value in the usual way, but if it doesn't contain a return
statement with a value then the object in the return declaration is
returned.

>4) Conversion of Type** to const Type**
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>It's ok, this is an error; but why cannot Type** be converted to const Type* 
>const* ?

It can in C++, but not in C.  It is in fact safe, but the discovery of
the problem with converting T** to T const** led to the present C rule,
which was cast in stone (figuratively) before the C++ rule was
developed.

-zefram
-- 
Andrew Main <zefram@dcs.warwick.ac.uk>


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