String has no c_str() ?!?

Projects Programming
1

Looking through the String class.. I can find no way to access the buffer pointer. wth? I just want a c_str() like function, or a const char * operator. I can't believe this would be omitted from a string class. I must have missed something?

2
3

You can use the STL string class, rather than the Arduino String class:

#include <iterator>
#include <string>
#include <pnew.cpp>

void setup ()
 {
   std::string foo = "Hello, world";
   
   Serial.begin (115200);
   Serial.println (foo.c_str ());
 }
 void loop () {}

Binary sketch size: 2576 bytes (of a 32256 byte maximum)

Or you can use the String class:

void setup ()
{
  String foo = "Hello, world";
   
  Serial.begin (115200);
  Serial.println (foo);
 }
 void loop () {}

Binary sketch size: 3522 bytes (of a 32256 byte maximum)

That uses quite a bit more memory, as you can see. Another 1000 bytes.

4

I didn't realize STL was available. Good info, thanks

5

You have to download and install it. Not a very big deal.

... copy all the files in the avr-stl\include directory into the hardware\tools\avr\avr\include subdirectory of the Arduino installation ...

6

@nick,
The link is not responding do you have a zip?

7

It seemed to work a minute ago, but I have a copy: