C struct as class member variable, zero "init" data in class constructor

[Alterah]

Hello,

So, at my work we use a static analysis tool and it is pointing out some uninitialized variables. One of which is a class member variable which is a C struct. Now, that variable is already declared in the header file for the class.

Currently in the class constructor I am doing:

memset( &thestruct, 0, sizeof( thestruct ) );

Is there a C++ way to do this? I Googled this but all I really found was:

StructDef thestruct = {};

Which doesn't really apply here. Thanks.

[VictorN]

In C++ you usually implement a (default and probably some other) ctor(s) in your structure and do the default and other initialization within the ctor(s)

[Alterah]

True, but I am dealing with a C struct and so wasn't quite sure.

[MrViggy]

Are you compiling the file as a 'C' file or a 'C++' file?

Viggy

[Alterah]

I'd have to say C++ because we use both C and C++ files when we build the executable.

[S_M_A]

Try adding a constructor to the struct. If you compile with C++ the compilation will succeed but in C it will not.

[D_Drmmr]

Is there a C++ way to do this? I Googled this but all I really found was:

StructDef thestruct = {};

Which doesn't really apply here. Thanks.

In an initializer list, you could use a function that returns an initialized instance of the struct. Something like

template <class T>
T MakeZeroInstance()
{
    T t = {};
    return t;
}

MyClass::MyClass()
: myStruct(MakeZeroInstance<MyStruct>())
{
}

[superbonzo]

you don't need to write a ctor, just use value-initialization that for a C-struct implies zero-initialization:

struct A{ /* ... */ };
struct B{ A a; B():a(){} }; // a is zero-initialized, eg: a's scalar members are set to zero