struct OBJECT
{
unsigned int Var1;
std::string Str1;
...
bool YesNo;
};
OBJECT Obj[ 327 ];
I am confused about how to zero-out Obj. It has several different type of elements. Do I have to set all of its member to 0?
Like... Obj[0].Str = "";
? So the question is, what is the proper way of doing it?
My attempt:
::memset( &Obj, 0, sizeof( Obj ) );
I am not sure if I am doing it correctly...
Oh and are there any faster way to zero-out an array?
Don't do it this way, because you have non trivial members in your struct (e.g. std::string). You can do this if all your members are only simple data types, like int, char, double or pointers.
The correct way for this type of struct is to define a constructor, which initializes all members properly
struct OBJECT {
OBJECT() : Var1(0), YesNo(false), ... {}
unsigned int Var1;
std::string Str1;
...
bool YesNo;
};
memset might even be dangerous, because it stomps over member's memory. See stackoverflow.com/q/2099692/1741542 for a discussion about uninitialized member variables.-Weffc++ option gives hundreds wrong warnings, valgrind is only useful in runtime whilst I'm working with app whose runtime is in embedded device. Perhaps cppcheck can be useful for this — not sure, I didn't try that specific problem.-Weffc++ nor cppcheck seem very reliable. -Weffc++ complains even when there's a default constructor for a non POD type, and it doesn't complain at all, when there's no constructor defined. cppcheck doesn't show any warning at all. Maybe newer versions are better.The "correct" way is to add a constructor method for your struct that initialises any member variables that don't have constructors of their own, e.g.:
OBJECT_STRUCT()
: Var1(0)
, YesNo(false)
{
}
In that example you'll note that Str1 was not initialised; this is because std::string has its own constructor that initialises it.
Either provide a custom default constructor or use the compiler defined default constructor:
std::fill(std::begin(Obj), std::end(Obj), OBJECT());
Note that the fill approach fill only work if you use the default constructor.
You should change your declaration to
struct OBJECT
{
unsigned int Var1;
std::string Str1;
...
bool YesNo;
OBJECT()
: Var1()
, Str1()
, ...
, YesNo(false)
{
// Do Nothing
}
};
The array - which you should use over std::array or std::vector - will initialise the objects.
memsetis not the way.std::stringwill panic if you 0 it out!