[SDL] IMG_LoadTyped_RW parameters

[Christoph Harder]

Hello,

I'm trying to write a small game, but when I call IMG_LoadTyped_RW it 
didn't work when I use std::string::c_str().
But when I use Image=IMG_LoadTyped_RW(SDL_RWFromFile(FileName.c_str(), 
"rb"), 1, "TGA"); it compiles.

Why doesn't it work?

Thanks in advance,
   Christoph

Code:
  #include <sdl/SDL.h>
  #include <sdl/SDL_image.h>
  ...
 
  class filesystem{
      protected:
          ...
      public:
          ...
          SDL_Surface loadTexture(string FileName, string FileType){
              SDL_Surface *Image;
              Image=IMG_LoadTyped_RW(SDL_RWFromFile(FileName.c_str(), 
"rb"), 1, FileType.c_str());
              return *Image;
          }
  }

Error:
   ...filesystem.h In member function `SDL_Surface 
engine::filesystem::loadTexture(std::string, std::string)':
   ...filesystem.h invalid conversion from `const char*' to `char*'
   ...filesystem.h initializing argument 3 of `SDL_Surface* 
IMG_LoadTyped_RW(SDL_RWops*, int, char*)'