convert std::string to gchar*?

[Slippy]

I am using webkitgtk in order to learn some C++ development skills in a small project.

I am having trouble converting a string to a gchar* in order to allow me to open up an URL.

I have searched the internet for a while and I am unable to find anything which actually works.

Thanks in advance.

[Lindley]

According to this,
http://developer.gnome.org/glib/2.28...pes.html#gchar

gchar is a typedef of the standard char type.

The std::string's c_str() method will return a const char* (and thus equivalently a const gchar*). However, if you need a non-const gchar* this isn't good enough.

For simply opening a URL, I can't imagine why the string would need to be modifiable, but unfortunately not every API enforces const-correctness properly.

One option is to do this:

string str;
vector<gchar> modifiable(str.c_str(),str.c_str()+str.length()+1);
func_needing_gchar_pointer(&modifiable[0]);

This of course implies making a copy, so it is not optimally efficient. Prefer just using c_str() when you can.

[laserlight]

It was not guaranteed until the latest edition of the C++ standard, but now that the contents of a std::string are stored contiguously, you could write:

string str;
// str would be given some suitable value here, with a terminating null character
// ...
func_needing_gchar_pointer(&str[0]);

Of course, as this requirement is new an older implementation of the standard library might not conform to this.

EDIT:
Then again, if the function is guaranteed not to change the contents of the string (i.e., it is merely not const-correct), then using c_str() with const_cast may be better.

[Slippy]

Thanks for the help, I will try this tonight after work when I get home.