warning #411: class foo defines no constructor to initialize the following:

Question

I have some legacy code built with c++ compiler giving the error in the subject line

typedef struct foo {
    char const * const str;
 } Foo;

and a lot of places in the code (meaning I cannot change all of them) use it in a C style initialization:

 Foo arr[] ={
     {"death"},
     {"turture"},
     {"kill"}
  }

What is the good workaround to remove the stupid warning?

Answer 1

You can't modify the const pointer after construction. You need a constructor initializer to initialize 'str'.

struct Foo
{
  const char* const str;
  explicit Foo(const char* str_) : str(str_) {}
};

Note that 'typedef' is not required in C++ for a case like this.

EDIT:

If you can't use a constructor, then you must make your pointer non-const:

struct Foo
{
  const char* str;
};

ANOTHER EDIT:

After litb's comment, I tried the original code and it does indeed compile (g++ 4.1.2 and XL C/C++ 8.0) with no warnings. Perhaps the compiler in question is doing a construction followed by assignment in this case? I used less violent strings, but I doubt that would make a difference. ;v)

Answer 2

Check the compiler's documentation to see if there's a workaround. Your code is perfectly compliant, so without any more information, it's impossible to help.

Answer 3

If it works anyway, you might as well disable the warning in the command line for those files.

With gcc I think it's something like -wd411.

Not so elegant, but if it works and if the code appears to be compliant to the standard (in this order) there's no point sweating over it!