struct with constructor: Compiler Warning.

[silversurfer2025]

Hello everyone,
I am using a struct inside another class, which can be used through an
empty constructor or another one. The definition looks like this:

struct Entry{
int index; //line 38
FeatureVector* value; //line 39
int object;
int count;
double variance;
Entry() {}
Entry(FeatureVector* _value, int _index, int _object, int _count,
double _variance)
: value(_value), index(_index), object(_object), count(_count),
variance(_variance) {}
};

When I am compiling I get the following error:

.../ModelContainer.h: In constructor 'Entry::Entry(FeatureVector*,
int, int, int, double)':
.../ModelContainer.h:39: warning: 'Entry::value' will be initialized
after
.../ModelContainer.h:38: warning: 'int Entry::index'
.../ModelContainer.h:44: warning: when initialized here

Why this? isn't it only initialized on calling the second constructor?
This should be no problem to me so why the warning?

Thanks a lot for your help

Tim

 

[Howard]

Hello everyone,
I am using a struct inside another class, which can be used through an
empty constructor or another one. The definition looks like this:

struct Entry{
int index; //line 38
FeatureVector* value; //line 39
int object;
int count;
double variance;
Entry() {}
Entry(FeatureVector* _value, int _index, int _object, int _count,
double _variance)
: value(_value), index(_index), object(_object), count(_count),
variance(_variance) {}
};

When I am compiling I get the following error:

../ModelContainer.h: In constructor 'Entry::Entry(FeatureVector*,
int, int, int, double)':
../ModelContainer.h:39: warning: 'Entry::value' will be initialized
after
../ModelContainer.h:38: warning: 'int Entry::index'
../ModelContainer.h:44: warning: when initialized here

Why this? isn't it only initialized on calling the second constructor?
This should be no problem to me so why the warning?

There's no problem. The warning is just to let you know that you put the
initializer for value before the initializer for index, but because index is
declared before value in the class, it will get initialized first.
Initializations occur in order of their declaration in the class.
(Personally, I'd disable that particular warning, if possible.)

-Howard

 

[tolgaceylanus]

I recommend reordering the initializer list to conform the declaration
order.
This is the recommended practice rather than turning off the compiler
warning in my opinion.

Tolga Ceylan

 

[Howard]

[please don't top-post. re-ordered]

I recommend reordering the initializer list to conform the declaration
order.
This is the recommended practice rather than turning off the compiler
warning in my opinion.

Yeah, that's probably a better option. (Not that it affects the resulting
binaries one way or the other, of course. )

-Howard

 

[silversurfer2025]

[please don't top-post. re-ordered]

I recommend reordering the initializer list to conform the declaration
order.
This is the recommended practice rather than turning off the compiler
warning in my opinion.

Oh, now I get the error,.. I simply did not think of this as being
warnable at all, but one never stops learning... Switched index and
value and everything is fine now..
Thanks
Tim