C++ Does Not Name A Type - c++

I get confused when I get errors like these
I have
FxSmartPtr<FxStreamable> able(FcNew,stream->StreamInObject());
FxGlobalPair pair(id,able);
I get an error on FxGlobalPair pair(id,able); that is able is not a type.
I tried modifying to
FxGlobalPair pair(id,FxSmartPtr<FxStreamable>::able);
but I get an error that is error: 'class FxSmartPtr<FxStreamable>::able' has not been declared
What concept am I missing?
UPDATE: typedef pair<FxID, FxSmartPtr<FxStreamable> > FxGlobalPair;
UPDATE 2:
Heading

I think that you have found the Most Vexing parse
The problem is that
FxSmartPtr able(FcNew,stream->StreamInObject());
may define a function named able, instead of a variable.

Related

'v8::Value::ToNumber': was declared deprecated

I'm trying to access a known object and get one of its properties as a Number
Unfortunately, the following code...
Isolate *isolate = args.GetIsolate();
Local<Object> opts = args[0]->ToObject();
Local<Number> mode = opts->Get(String::NewFromUtf8(isolate, "mode"))->ToNumber();
is giving the following warning:
warning C4996: 'v8::Value::ToNumber': was declared deprecated
....node-gyp\8.5.0\include\node\v8.h(9578): note: see declaration of 'v8::Value::ToNumber'
In the v8.h I noticed the comment on ToNumber: "Use maybe version". I've attempted to convert it to a Maybe but I've not yet been able to get any attempt to compile correctly. What is the correct approach to using Maybe and getting the Number object?
Looks like the "Use maybe version" comment in the v8.h led me in the wrong direction. The deprecate notice seems to apply to the method-overload that is missing the isolate. If you pass the isolate...
->ToNumber(isolate);
it works without warning.

conversion to '__uint8_t' from '__uint32_t' may alter its value in Eclipse

I get a problem when i trying to add the __stm32cube lib__ to my eclipse project.
#define __HAL_RCC_HSE_CONFIG(__STATE__) (*(__IO uint8_t *)RCC_CR_BYTE2_ADDRESS = (__STATE__))
There is a error for this definition says
__conversion to '__uint8_t' from '__uint32_t' may alter its value__
.
I tried to add an _int8_t but still show up this error. Any one knows how to solve this problem?
There is a predefine __define RCC_CR_BYTE2_ADDRESS ((uint32_t)0x40023802)__
Thanks in advance!

error: ‘struct arphdr’ has no member named ‘ar_sha’

I'm creating my own ARP eader with below shown code, however this code ain't working, I get error message as ‘struct arphdr’ has no member named ‘ar_sha’, ar_spa, ar_tha, ar_tpa. I've checked net/if_arp.h, these members are part of struct arphdr. Why i'm unable to use them?? Please assist.
arp.ar_hrd=htons(ARPHRD_ETHER);
arp.ar_pro=htons(ETHERTYPE_IP);
arp.ar_hln=6;
arp.ar_pln=4;
arp.ar_op=htons(ARPOP_REQUEST);
arp.ar_sha=ether_aton("ss:ss:ss:ss:ss:ss");
arp.ar_spa=inet_addr("192:168:32:128");
arp.ar_tha=ether_aton("ff:ff:ff:ff:ff:ff");
arp.arp_tpa=inet_addr("192.168.32.1");

Resolving module name conflicts, need to get at ORD_MAP signature

I'm working on a relatively large SML codebase. It was originally written to compile with MLton, but I'm now working with it under SML/NJ. I need to use RedBlackMapFn, which is defined in smlnj-lib.cm. However, I get an error:
elaborate/elaborate-bomenv.fun:9.20-9.27 Error: unbound signature: ORD_KEY
elaborate/elaborate-bomenv.fun:14.21-14.40 Error: unbound functor: RedBlackMapFn
elaborate/elaborate-bomenv.fun:32.20-32.27 Error: unbound signature: ORD_KEY
elaborate/elaborate-bomenv.fun:37.21-37.40 Error: unbound functor: RedBlackMapFn
So I assume that smlnj-lib.cm is not being pulled by CM. In an effort to fix this, I added $/smlnj-lib.cm to the sources.cm file in the directory that I'm working in. This causes a separate issue:
elaborate/sources.cm:25.1-25.18 Error: structure Random imported from $SMLNJ-LIB/Util/smlnj-lib.cm#243997(random.sml) and also from ./(sources.cm):lib/(sources.cm):basic/(sources.cm):random.sml
elaborate/sources.cm:25.1-25.18 Error: structure Queue imported from $SMLNJ-LIB/Util/smlnj-lib.cm#436143(queue.sml) and also from ./(sources.cm):lib/(sources.cm):basic/(sources.cm):two-list-queue.sml
No dice. I tried removing the Random structure that's coming from ./(sources.cm):lib/(sources.cm):basic/(sources.cm):random.sml, but it appears that it isn't equivalent to the one defined in the standard library, so I can't just substitute one for the other.
I'd like to use something like Python's import ... from ... as ...
mechanism to give a new name to the Random that's coming from the standard library, but CM's documentation doesn't offer any hints as to how I'd go about that.
How can I resolve a module naming conflict across multiple SML files?
I ended up splitting off the problematic file in to a separate .cm. The problem file here is elaborate-bomenv.{sig, fun}. The .cm file for this directory is sources.cm, which caused errors when it looked like:
Group
...
is
$/basis.cm
...
elaborate-bomenv.fun
elaborate-bomenv.sig
...
So instead, I made an elaborate-bomenv-sources.cm that looks like:
Group
signature ELABORATE_BOMENV
functor BOMEnv
is
$/smlnj-lib.cm
...
elaborate-bomenv.sig
elaborate-bomenv.fun
and changed the original sources.cm to read:
Group
...
is
$/basis.cm
...
./elaborate-bomenv-sources.cm
...
Which is ugly, but it works.

error: enum was not declared in this scope

I added a new value (NULL_IS_NOT_NIL) to an enum in ksql.h
enum
{
PKEY = 0x000001,
NONCOLUMN = 0x000010,
EXPRESSION = 0x000010,
INSERTONLY = 0x000100,
NUMERIC = 0x001000,
NULL_IS_NOT_NIL = 0x010000,
MAXLEN_TABLENAME = 50
};
Unfortunately, this:
Row.SetExtras ("COMMENT2", KROW::NULL_IS_NOT_NIL);
Throws an error.
db.cpp:7727: error: âNULL_IS_NOT_NILâ was not declared in this scope
On the other hand
Row.SetExtras ("COMMENT2", 0x010000);
and
Row.SetExtras (vendor_id, KROW::NUMERIC);
Both work fine and do not throw errors. Right now I can get by by replacing NULL_IS_NOT_NIL with 0x010000, but that is a bad idea. Is there a reason that I am getting this error? Have I missed something obvious?
You've made the changes in the header file, but they are not being reflected in your project. As stated in the comments, the cause was due to it not being pushed to the right folder.
You forgot to give the enum a name: KROW is missing from your code snippet.
On the other hand, if you call it KROW, you will get a redefinition error. So you need to come up with a different solution. (Unless you are editing the system header file directly -- but surely not...)