A good C equivalent of STL vector?

glib provides an GArray type, which implements a dynamically growing array. If you can use external 3rd party libraries, glib is almost always a good choice as "standard" library for C. It provides types for all basic data structures, for unicode strings, for date and time values, and so on.

here a simple vector-replacement, its ONE function for all, its strictly C89 and threadsafe;libs are too difficult for me, i use my own;no performance, but easy to use

/* owner-structs too */typedef struct {  char name[20],city[20];  int salary;} My,*Myp;typedef char Str80[80];/* add here your type with its size */typedef enum {SPTR,INT=sizeof(int),DOUBLE=sizeof(double),S80=sizeof(Str80),MY=sizeof(My)} TSizes;typedef enum {ADD,LOOP,COUNT,FREE,GETAT,GET,REMOVEAT,REMOVE} Ops;void *dynarray(char ***root,TSizes ts,Ops op,void *in,void *out){  size_t d=0,s=in?ts?ts:strlen((char*)in)+1:0;  char **r=*root;  while( r && *r++ ) ++d;  switch(op) {  case ADD:   if( !*root ) *root=calloc(1,sizeof r);              *root=realloc(*root,(d+2)*sizeof r);              memmove((*root)+1,*root,(d+1)*sizeof r);              memcpy(**root=malloc(s),in,s);              break;  case LOOP:  while( d-- ) ((void (*)(char*))in)((*root)[d]); break;  case COUNT: return *(int*)out=d,out;  case FREE:  if(r) {                ++d; while( d-- ) realloc((*root)[d],0);                free(*root);*root=0;              } break;  case GETAT: { size_t i=*(size_t*)in;                if(r && i<=--d)                  return (*root)[d-i];              } break;  case GET:   { int i=-1;                while( ++i,d-- )                if( !(ts?memcmp:strncmp)(in,(*root)[d],s) )                  return *(int*)out=i,out;                return *(int*)out=-1,out;              }  case REMOVEAT: { size_t i=*(size_t*)in;                   if(r && i<=--d) {                     free((*root)[d-i]);                     memmove(&(*root)[d-i],&(*root)[d-i+1],(d-i+1)*sizeof r);                     return in;                   }                 } break;  case REMOVE: while( *(int*)dynarray(root,ts,GET,in,&d)>=0 )                 dynarray(root,ts,REMOVEAT,&d,0);  }  return 0;}void outmy(Myp s){  printf("\n%s,%s,%d",s->name,s->city,s->salary);}main(){  My    z[]={{"Buffet","Omaha",INT_MAX},{"Jobs","Palo Alto",1},{"Madoff","NYC",INT_MIN}};  Str80 y[]={ "123","456","7890" };  char **ptr=0;  int x=1;  /* precondition for first use: ptr==NULL */  dynarray(&ptr,SPTR,ADD,"test1.txt",0);  dynarray(&ptr,SPTR,ADD,"test2.txt",0);  dynarray(&ptr,SPTR,ADD,"t3.txt",0);  dynarray(&ptr,SPTR,REMOVEAT,&x,0); /* remove at index/key ==1 */  dynarray(&ptr,SPTR,REMOVE,"test1.txt",0);  dynarray(&ptr,SPTR,GET,"t3.txt",&x);  dynarray(&ptr,SPTR,LOOP,puts,0);  /* another option for enumerating */  dynarray(&ptr,SPTR,COUNT,0,&x);    while( x-- )      puts(ptr[x]);  dynarray(&ptr,SPTR,FREE,0,0); /* frees all mallocs and set ptr to NULL */  /* start for another (user)type */  dynarray(&ptr,S80,ADD,y[0],0);  dynarray(&ptr,S80,ADD,y[1],0);  dynarray(&ptr,S80,ADD,y[2],0);  dynarray(&ptr,S80,ADD,y[0],0);  dynarray(&ptr,S80,LOOP,puts,0);  dynarray(&ptr,S80,FREE,0,0); /* frees all mallocs and set ptr to NULL */  /* start for another (user)struct-type */  dynarray(&ptr,MY,ADD,&z[0],0);  dynarray(&ptr,MY,ADD,&z[1],0);  dynarray(&ptr,MY,ADD,&z[2],0);  dynarray(&ptr,MY,ADD,&z[0],0);  dynarray(&ptr,MY,LOOP,outmy,0);  dynarray(&ptr,MY,FREE,0,0);  return 0;}

There is sglib, which implements various lists,hashmaps and rbtrees in a generic fashion (i.e. by specializing over a type). There is also a fast sorting function for arrays:

• http://sglib.sourceforge.net/