'string' in function prototype

[ChuckB]

Hi,

Here is a small portion of code that results in an error message "'string' was not declared in this scope".

#include <string.h>
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
using namespace std;
 
bool ReadBitmap(string);  //<------------ doesn't like this

int main(int argc, char *argv[])
{
  if(ReadBitmap("bg.bmp")==false) return 0; //read file...return if not opened
  system("pause");
  return 0;
}

Any regular type in the prototype such as char, float, long, etc would be acceptable. But 'strings' aren't well liked. I can do this with 'char' but would like strings since I am a VB dependent programmer. ;-)

So, I imagine there is something 'special' that I must do for this prototype. It probably involves some C++ wierd thing that I am still learning such as... **, (void), ->,*(char*), ., :: :-)

Looking for help.
Regards,
ChuckB

[The Hobo]

drop the .h on <string.h>

possibly even for the other ones if that alone doesn't help.

having .h on the end and using namespace std don't go well together.

[ChuckB]

Hobo,
Thanks for responding so quickly. That did it. Thanks!

Regards,
ChuckB

[Zaei]

Chuck, all of the new standard headers are without the .h. So, you have <vector>, <list>, <iostream>, <string>, <map>, etc, etc. The .h versions are just there for compatability's sake.

Also, if you are just using one or two classes from the std namespace, you can use this syntax:

#include <vector>
#include <string>
using std::vector;
using std::string;

Doing it this way keeps your global namespace clear.

Z.

[ChuckB]

Hi Z,
Thanks for the tip. I have been studying lots of C/C++ code in the past couple of months and only now is it getting straightened out. I have no idea how I learned to program in the 80's without the internet and forums such as these. :-)

Incidently, I wrote my first 'vector' program tonight demonstrating various uses of vectors and I finally get it. I like the 'dynamic resizing' with push_back(). Really nice.

The code in this thread is helping me to read a bitmap which I will place into a vector instead of an array so I can load my first .bmp textures into my OpenGL stuff.

One last note, do you realize I now have collected three 3" binders full of notes and tutorials I have collected just learning C++? Gotta figure out how to archive this stuff in an easily retrievable manner.

Regards,
ChuckB

[Zaei]

::taps head:: practice... after a while, it all comes naturally =).

That is a LOT of notes =).

Same thing with this twistiness. At first its just a bunch of gobbldegoop, but after a while, how thing interact start to make sense, and it just opens door after door.

Z.

[parksie]

Originally posted by ChuckB
The code in this thread is helping me to read a bitmap which I will place into a vector instead of an array so I can load my first .bmp textures into my OpenGL stuff.

You're still better off loading it into an array, it's *far* faster, and you shouldn't need the dynamic sizing :-/

[ChuckB]

Parksie,
I didn't know arrays were faster then vectors. BUT, I know see the distinction. Let me know if this is correct or not.

If I am loading vertices for a 3D model in which the number of vertices may vary from model to model, I can do two things.

1. Encode the number of vertices in a number at the top of an ASCII/Binary file. Read this number and then create array of that size and load this data into the array.
2. Read the data into vector when I don't know the size using push_back();

For bitmap (.bmp) files, I can read the headers, get the actual size of the bitmap image, so there is no guess work. I simply create an array/vector of that size.

Right?

Regards,
ChuckB

[Zaei]

Easier and faster to encode the number at the top of the file.

Z.

[parksie]

For the points, use a vector.

For the bitmap, use an array