C structure as a data type

Question

I want to be able to do something like this:

typedef struct
{
    char* c_str;

} string;

string s = "hello";

Is it possible to do that in any way?

I know that it is possible to do this:

typedef struct
{
    char* c_str;

} string;

string s = { "hello" };

But I do not like the curly brackets when it is only one member variable.

Answer 1

You could use a typedef instead of a struct:

typedef char* string;
string s = "hello";

But then const string would make the pointer const, and not the pointed-to data. So const string s is equivalent to char* const s. A solution may be to define an additional type for const strings:

typedef char* string;
typedef const char* const_string;

For the original struct, the same is true. (C++ has the same "problem", which is why it has iterator and const_iterator in its container types.)

An advantage of a typedef for a pointer type is that you can type

string s1, s2, s3;

instead of

char *s1, *s2, *s3;

Answer 2

In C, it is not possible, but you can do it in C++ if you add constructor that takes one appropriate parameter. Compiler will do the rest. You can mark the constructor as explicit if you want to avoid this implicit conversion behaviour.

In C++:

struct string {

    char * m_c_str;

    /* explicit */ string(char* c_str) : m_c_str(c_str) { }
};

int main(int argc, char * argv[]) {

    string s = "hello";

    return 0;

}