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digitalmars.D - Idea: Use out/inout when _calling_ functions as well

reply "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
Was skimming through some C# source today, and I noticed something like 
this:

SomeClass c;
func(5, 10, out c);

I remember someone saying that out and inout are great, but if you're not 
familiar with the code, you may not know which parameters are going to be 
modified by the function.  At least in C++ you have to use the address-of 
operator, so that's usually a clue that something's going to happen to it. 
But in D, there is no indication as to which parameters are in, out, or 
inout, unless you look at the function declaration.

I think it'd be a good idea to enforce the use of out and inout on 
parameters which are passed as such.  It serves to self-document the code 
and it makes it explicit that something is going to happen to the parameter.
May 14 2005
next sibling parent reply Vathix <vathix dprogramming.com> writes:
 I think it'd be a good idea to enforce the use of out and inout on
 parameters which are passed as such.  It serves to self-document the code
 and it makes it explicit that something is going to happen to the  
 parameter.



I like it. I think I proposed this before. Maybe at least make it  
optional: if specified, it must be correct.
May 14 2005
next sibling parent "Unknown W. Brackets" <unknown simplemachines.org> writes:
I like that idea.  What else could "in", "inout" or, "out" mean there?

Just like they're optional in the function declaration.

-[Unknown]



 I think it'd be a good idea to enforce the use of out and inout on
 parameters which are passed as such.  It serves to self-document the code
 and it makes it explicit that something is going to happen to the  
 parameter.



 
 I like it. I think I proposed this before. Maybe at least make it  
 optional: if specified, it must be correct.
May 14 2005
prev sibling next sibling parent Thomas Kuehne <thomas-dloop kuehne.thisisspam.cn> writes:
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Hash: SHA1

Vathix schrieb am Sat, 14 May 2005 18:17:04 -0400:

 I think it'd be a good idea to enforce the use of out and inout on
 parameters which are passed as such.  It serves to self-document the code
 and it makes it explicit that something is going to happen to the  
 parameter.



 I like it. I think I proposed this before. Maybe at least make it  
 optional: if specified, it must be correct.



The optional solution could be nice for catching logical bugs at compile
time.

Thomas

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May 17 2005
prev sibling parent reply Hasan Aljudy <hasan.aljudy gmail.com> writes:
Vathix wrote:

 I think it'd be a good idea to enforce the use of out and inout on
 parameters which are passed as such.  It serves to self-document the code
 and it makes it explicit that something is going to happen to the  
 parameter.



 
 I like it. I think I proposed this before. Maybe at least make it  
 optional: if specified, it must be correct.



I don't mind, as long as it's optional.
May 17 2005
parent reply Piotr Fusik <Piotr_member pathlink.com> writes:
I don't mind, as long as it's optional.



No, it shouldn't be optional.
May 18 2005
parent Hasan Aljudy <hasan.aljudy gmail.com> writes:
Piotr Fusik wrote:

I don't mind, as long as it's optional.



 
 No, it shouldn't be optional.
 
 



To me, that just adds complexity that's not really necessary.
May 18 2005
prev sibling parent "Ben Hinkle" <ben.hinkle gmail.com> writes:
"Jarrett Billingsley" <kb3ctd2 yahoo.com> wrote in message 
news:d65hlc$1ket$1 digitaldaemon.com...

 Was skimming through some C# source today, and I noticed something like 
 this:

 SomeClass c;
 func(5, 10, out c);

 I remember someone saying that out and inout are great, but if you're not 
 familiar with the code, you may not know which parameters are going to be 
 modified by the function.  At least in C++ you have to use the address-of 
 operator, so that's usually a clue that something's going to happen to it. 
 But in D, there is no indication as to which parameters are in, out, or 
 inout, unless you look at the function declaration.

 I think it'd be a good idea to enforce the use of out and inout on 
 parameters which are passed as such.  It serves to self-document the code 
 and it makes it explicit that something is going to happen to the 
 parameter.



'out' or 'inout' at the call site would also enable an overloadable 
opIndexMutable for expressions like
func(5,10,out x["hello"]);
where x is a user-defined type. Currently there is no way to use overloaded 
indexing as an lvalue. See the thread about opIndexMutable started by Kevin 
Bealer last month.
May 14 2005