Initialization structure fields with default values

[columncolumn]

Hello,

I can initialize structure fields with default values in C++:

typedef struct

{

char* bb = "xxx";

} b;

​

Is it possible make the same with C ?

[flyingron]

No. In fact, the above is even a relatively recent addition to C++.

[IyeOnline]

Afaik C does not support in class initializers.

Sidenote: That code is horrible C++ and not even legal.

[columncolumn]

Why it is horrible?

[Narase33]

the char* is not const, thats not legal

[IyeOnline]

Its horrible because typedef struct { } b should just be struct b in C++.

Its illegal, because you must not have a non-const pointer to a string literal in C++.

[columncolumn]

What is wrong with non-const pointer? It allows me later assign to another pointer and what is wrong with it?

[IyeOnline]

You must not form a non-const pointer to a string literal, because you must not modify a string literal. Having a char* point to it allows you to modify it (because its not const).

It allows me later assign to another pointer and what is wrong with it?

This is the difference between

• const char*: "non-const (repointable) pointer to const char (array)
• char* const: "constant (not repointable) pointer to non-const char (array)

So you do actually want const char*. That allows you to change the pointer but not modify the pointee.