- void (*set_parameter)(struct _gfxdocument*gfx, char*name, char*value);
- char* (*getinfo)(struct _gfxdocument*gfx, char*key);
+ void (*set_parameter)(struct _gfxdocument*gfx, const char*name, const char*value);
+ char* (*getinfo)(struct _gfxdocument*gfx, const char*key);