function prototype

When I use 1st line in prototypes, compiler fails because SDL_GL_GetProcAddress return (void*)
When I use 2nd line in prototypes, compiler fails in last line because (void*) is not a function prototype.
So, what cast I must use?
Can you rewrite these 3 lines correctly?
With 1st line in prototypes, I used:
glCompressedTexImage2DARB =
(void (*glCompressedTexImage2DARB)
(GLenum, GLint, GLenum, GLsizei, GLsizei, GLint, GLsizei, const void*))
SDL_GL_GetProcAddress("glCompressedTexImage2DARB") ;
but it does not work
-------------------------------------------------------------------------
//prototypes
void (*glCompressedTexImage2DARB) (GLenum, GLint, GLenum, GLsizei, GLsizei, GLint, GLsizei, const void*);
//void *glCompressedTexImage2DARB;

//load function
glCompressedTexImage2DARB = SDL_GL_GetProcAddress("glCompressedTexImage2DARB") ;

//use function
glCompressedTexImage2DARB(GL_TEXTURE_2D, z, dxt_f, width, height, 0, size, (byte*) tex + offset);

[red floyd]

<- Chameleon -> wrote:

When I use 1st line in prototypes, compiler fails because SDL_GL_GetProcAddress return (void*)
When I use 2nd line in prototypes, compiler fails in last line because (void*) is not a function prototype.
So, what cast I must use?
Can you rewrite these 3 lines correctly?
With 1st line in prototypes, I used:
glCompressedTexImage2DARB =
(void (*glCompressedTexImage2DARB)
(GLenum, GLint, GLenum, GLsizei, GLsizei, GLint, GLsizei, const void*))
SDL_GL_GetProcAddress("glCompressedTexImage2DARB") ;
but it does not work
-------------------------------------------------------------------------
//prototypes
void (*glCompressedTexImage2DARB) (GLenum, GLint, GLenum, GLsizei, GLsizei, GLint, GLsizei, const void*);
//void *glCompressedTexImage2DARB;

//load function
glCompressedTexImage2DARB = SDL_GL_GetProcAddress("glCompressedTexImage2DARB") ;
glCompressedTexImage2DARB = reinterpret_cast<void (*)(GLenum ,GLint,
GLenum, Glsizei, const void
*)>(SDL_GL_GetProcAddress("glCompressedTexImage2DA RB"));
//use function
glCompressedTexImage2DARB(GL_TEXTURE_2D, z, dxt_f, width, height, 0, size, (byte*) tex + offset);