Add features about adding/inserting multiple elements or array content

[Lasereyes5]

Thanks for creating this simple and useful library.
I try to use the char vector as string with this library, but it lacks some features. I think these features will also be helpful in dealing array and multiple elements, so I implement them.

I don't know if you need or want these features, so feel free to judge.

Added Symbols

These are macros and functions added:

// macros
// with typeof()
vector_add_dst_multiple(vec_addr, count)
vector_insert_dst_multiple(vec_addr, pos, count)
vector_add_multiple(vec_addr, ...)
vector_add_arr(vec_addr, arrptr, count)
vector_insert_multiple(vec_addr, pos, ...)
vector_insert_arr(vec_addr, pos, arrptr, count)
// without typeof()
vector_add_dst_multiple(vec_addr, type, count)
vector_insert_dst_multiple(vec_addr, type, pos, count)
vector_add_multiple(vec_addr, type, ...)
vector_add_arr(vec_addr, type, listptr, count)
vector_insert_multiple(vec_addr, type, pos, ...)
vector_insert_arr(vec_addr, type, pos, arrptr, count)


// functions
// public
void* _vector_add_dst_multiple(vector* vec_addr, vec_type_t type_size, vec_size_t reuire_count);
void* _vector_insert_dst_multiple(vector* vec_addr, vec_type_t type_size, vec_size_t pos, vec_size_t reuire_count);
// private
bool vector_has_multiple_space(vector_header* h,vec_size_t reuire_count);
vector_header* vector_realloc_require(vector_header* h, vec_type_t type_size, vec_size_t reuire_count);

Disadventages

The macro vector_add_multiple and vector_insert_multiple uses two C99 features called "Variadic Macros" and "Compound Literals" to accept multiple elements and create a temprory array, basicly like this:

#define vector_mkarr(type, ...) (type[]){__VA_ARGS__}
// expand to "(int[]){1,2,3}"
vector_mkarr(int, 1, 2, 3)

I haven't test it in MSVC (or C++ in MSVC) yet, so I don't know if this will causes problems.

The descriptions and names about these actions are quite long to fit the sheets in README file, may get a mess or force other lines align longer.

Adventages

Add/Insert multiple items or array content directly:

int* foo = vector_create();
int a[] = {3,4,5};
int b[] = {5,12,13,-1};

vector_add(&foo, 5);
vector_add_multiple(&foo, 5, 6, 8);
vector_add_arr(&foo, a, 3);

int insert_pos = 2;
vector_insert_multiple(&foo, insert_pos, -15, -61, -78);
vector_insert_arr(&foo, insert_pos, b, 4);

Now I can use the char vector as string more easily:

char* str_vec = vector_create();

// add string
const char s[] ="char vector as string test";
vector_add_arr(&str_vec, s, sizeof(s));
// vector_add_arr(&str_vec, s, strlen(s));
// vector_add(&str_vec, '\0');

// insert string
const char s2[] = "(inserting)"
int insert_pos = sizeof("char vector");// a trick about indexing a string
vector_insert_arr(&str_vec, insert_pos, s2, strlen(s2));

printf("string vector:\"%s\"\n", str_vec);
vector_free(str_vec);

It even supports adding/inserting structs directly, since I uses memcpy to implement this instead of for loop.
It uses like this:

// just an example
typedef struct size
{
	int x;
	int y;
} size;

size *size_vec = vector_create();
size a = {1,2}, b = {-3,7};
// parsing in the pointer of item and the count "1" to pretend it's an array.
vector_add_arr(&size_vec, &a, 1);
vector_add_multiple(&size_vec, b);
vector_add_multiple(&size_vec, (size){-65,39}, (size){12,-87});
/*
// or in regular way with index:
size *sizes = vector_add_dst_multiple(&size_vec, 2);
sizes[0].x = 1;
sizes[0].y = 2;
sizes[1].x = -3;
sizes[1].y = 7;
sizes = NULL;
*/

for (int i = 0, vecsize = vector_size(size_vec); i < vecsize; i++)
{
	printf("(%d,%d)\n", size_vec[i].x, size_vec[i].y);
}
vector_free(size_vec);

Note: I thought it would causes problems to make temporary structs in macro, but it eventually works in a tricky way.

For example, the struct arguments in vector_add_multiple(&size_vec, (size){-65,39}, (size){12,-87}); will break down into"(size){-65" "39}" "(size){12" "-87}", and join back again in __VA_ARGS__. So this won't affect any structure in arguments even with structs.