digitalmars.D.learn - Why isn't my dynamic array method doesn't work for this type?
- rempas (124/124) May 05 2022 I have created a structure that is a actually an array that
- vit (7/16) May 05 2022 ```d
- vit (16/33) May 05 2022 ```d
- rempas (4/10) May 05 2022 Oh, right! I forgot to say it. I'm using my own `realloc` and not
- Steven Schveighoffer (3/4) May 05 2022 Your assignment operator does nothing.
- rempas (5/7) May 05 2022 Thanks! That was indeed the problem! In the other data
- Steven Schveighoffer (12/19) May 06 2022 You don't need to declare an assign operator, the default for structs is...
- rempas (5/16) May 06 2022 Hah! For some reason, I had the idea that it doesn't work
- colleen camacho (8/17) May 05 2022 can i use method of Dynamic array in C using malloc library
- rempas (3/10) May 06 2022 Thanks for your time! Thankfully, my problem was fixed thanks to
I have created a structure that is a actually an array that
allocates memory and growths. It is a template and it has worked
with a couple of types that I have tried with. It doesn't work
with one tho and I cannot understand why. I will list the
smallest possible code I could. Keep in mind that it is a couple
of code. For anyone that wants to read it, keep in mind that I
have to make this code work with LDC and using "-betterC".
// Filename: "test_file"
```aneluhaein```
// Filename: "my_file.d"
```d
import vec;
struct My_File {
char tok;
const char* contents;
ulong size, ln, cn, pos, identation;
ref My_File opAssign(ref const My_File s) return { return this;
}
// Copy constructor
this(ref return scope My_File rhs) {
this.tok = rhs.tok;
this.contents = rhs.contents;
this.ln = rhs.ln;
this.cn = rhs.cn;
this.pos = rhs.pos;
this.identation = rhs.identation;
}
debug {
void print() {
printf("
this.tok = %c
this.contents = \n\n`\n%s`
this.ln = %lu
this.cn = %lu
this.pos = %lu
this.identation = %lu",
this.tok,
this.contents,
this.ln,
this.cn,
this.pos,
this.identation,
);
}
}
}
```
// Filename: "vec.d"
```d
public import core.stdc.stdlib;
public import core.stdc.stdio;
public import core.sys.posix.fcntl;
public import core.sys.linux.sys.mman;
public enum DEF_VEC_REALLOC_SIZE = 3;
public enum DEF_VEC_ALLOC_SIZE = 3;
void exit_prog(int code) {
exit(0);
}
struct Vector(T) {
T* ptr; // The pointer to the data
ulong capacity; // Total amount of objects we can store
ulong length; // The amount of the objects we have stored
this(ulong capacity) { // Only used to create the vector that
will hold the files
this.length = 0;
this.capacity = capacity;
this.ptr = cast(T*)malloc(T.sizeof * capacity);
if (!this.ptr) { // Allocation error check
fprintf(stderr, "Error: Could not allocate memory for the
*%s object! Exiting...\n",
cast(char*)(T).stringof);
exit_prog(1);
}
}
void add(T element) {
if (this.capacity > this.length) {
this.ptr[this.length++] = element;
}
else {
this.capacity += DEF_VEC_REALLOC_SIZE;
realloc(this.ptr, T.sizeof * DEF_VEC_REALLOC_SIZE);
if (!this.ptr) { // Re-allocation error check
fprintf(stderr, "Error: Could not allocate more memory
for the *%s object! Exiting...",
cast(char*)(T).stringof);
exit_prog(1);
}
}
}
void inc() {
this.ptr++;
this.length--;
}
}
```
// Filename: "main.d"
```d
import core.stdc.stdlib;
import core.stdc.stdio;
import my_file;
import vec;
extern (C) void main() {
auto modules = Vector!(My_File)(DEF_VEC_ALLOC_SIZE);
const char* filename = "/tmp/test_file";
int fd = open(filename, O_RDWR);
ulong file_size = 24;
const char* contents = cast(char*)mmap(null,
file_size, PROT_READ, MAP_PRIVATE, fd, 0
);
My_File file = {
'T',
contents,
file_size,
1, 2, 3, 4
};
debug printf("\n\nBEFORE ADDING IT TO THE MODULE\n");
file.print();
modules.add(file);
debug printf("\n\n\nAFTER ADDING IT TO THE MODULE\n");
modules.ptr.print();
puts("");
exit(0);
}
```
May 05 2022
On Thursday, 5 May 2022 at 10:40:44 UTC, rempas wrote:I have created a structure that is a actually an array that allocates memory and growths. It is a template and it has worked with a couple of types that I have tried with. It doesn't work with one tho and I cannot understand why. I will list the smallest possible code I could. Keep in mind that it is a couple of code. For anyone that wants to read it, keep in mind that I have to make this code work with LDC and using "-betterC". [...]```d this.capacity += DEF_VEC_REALLOC_SIZE; //realloc(this.ptr, T.sizeof * DEF_VEC_REALLOC_SIZE); this.ptr = realloc(this.ptr, T.sizeof * this.capacity); //<<-- ```
May 05 2022
vit <vit vit.vit> On Thursday, 5 May 2022 at 11:49:29 UTC, vit wrote:On Thursday, 5 May 2022 at 10:40:44 UTC, rempas wrote:```d void add(T element) { if (this.capacity == this.length) { this.capacity += DEF_VEC_REALLOC_SIZE; this.ptr = realloc(this.ptr, T.sizeof * this.capacity); if (!this.ptr) { // Re-allocation error check fprintf(stderr, "Error: Could not allocate more memory for the *%s object! Exiting...", cast(char*)(T).stringof); exit_prog(1); } } this.ptr[this.length++] = element; } ```I have created a structure that is a actually an array that allocates memory and growths. It is a template and it has worked with a couple of types that I have tried with. It doesn't work with one tho and I cannot understand why. I will list the smallest possible code I could. Keep in mind that it is a couple of code. For anyone that wants to read it, keep in mind that I have to make this code work with LDC and using "-betterC". [...]```d this.capacity += DEF_VEC_REALLOC_SIZE; //realloc(this.ptr, T.sizeof * DEF_VEC_REALLOC_SIZE); this.ptr = realloc(this.ptr, T.sizeof * this.capacity); //<<-- ```
May 05 2022
On Thursday, 5 May 2022 at 11:49:29 UTC, vit wrote:
```d
this.capacity += DEF_VEC_REALLOC_SIZE;
//realloc(this.ptr, T.sizeof * DEF_VEC_REALLOC_SIZE);
this.ptr = realloc(this.ptr, T.sizeof * this.capacity);
//<<--
```
Oh, right! I forgot to say it. I'm using my own `realloc` and not
the one from libc. So, the `realloc` function is not the problem
here.
May 05 2022
On 5/5/22 6:40 AM, rempas wrote:
ref My_File opAssign(ref const My_File s) return { return this; }
Your assignment operator does nothing.
-Steve
May 05 2022
On Thursday, 5 May 2022 at 14:20:49 UTC, Steven Schveighoffer wrote:Your assignment operator does nothing. -SteveThanks! That was indeed the problem! In the other data structures, it worked without needing explicitly provide one so I didn't thought about it. Thanks a lot, you're saving me!
May 05 2022
On 5/5/22 4:27 PM, rempas wrote:On Thursday, 5 May 2022 at 14:20:49 UTC, Steven Schveighoffer wrote:You don't need to declare an assign operator, the default for structs is to member-wise copy all the values. However, if you do provide one, it will be used. Note that a simple default can be done like: ```d ref My_File opAssign(ref My_File s) return { this.tupleof = s.tupleof; return this; } ``` -SteveYour assignment operator does nothing.Thanks! That was indeed the problem! In the other data structures, it worked without needing explicitly provide one so I didn't thought about it. Thanks a lot, you're saving me!
May 06 2022
On Friday, 6 May 2022 at 13:35:13 UTC, Steven Schveighoffer wrote:
You don't need to declare an assign operator, the default for
structs is to member-wise copy all the values.
However, if you do provide one, it will be used.
Note that a simple default can be done like:
```d
ref My_File opAssign(ref My_File s) return {
this.tupleof = s.tupleof;
return this;
}
```
-Steve
Hah! For some reason, I had the idea that it doesn't work
(meaning it won't compile) without providing an assignment
operator and that I had test it. I now tested it again and it is
indeed as you say. Thank you!
May 06 2022
On Thursday, 5 May 2022 at 10:40:44 UTC, rempas wrote:I have created a structure that is a actually an array that allocates memory and growths. It is a template and it has worked with a couple of types that I have tried with. It doesn't work with one tho and I cannot understand why. I will list the smallest possible code I could. Keep in mind that it is a couple of code. For anyone that wants to read it, keep in mind that I have to make this code work with LDC and using "-betterC". [...]can i use method of Dynamic array in C using malloc library function. Program example will create an integer array of any length dynamically by asking the array size and array elements from user and display on the screen.how memory allocation in C programming is done at run time with examples. to integrate an api of tracking number like [intelcom courrier canada inc tracking](https://couriertrackingfinder.com/intelcom-express-tracking/)?
May 05 2022
On Thursday, 5 May 2022 at 21:07:22 UTC, colleen camacho wrote:can i use method of Dynamic array in C using malloc library function. Program example will create an integer array of any length dynamically by asking the array size and array elements from user and display on the screen.how memory allocation in C programming is done at run time with examples. to integrate an api of tracking number like [intelcom courrier canada inc tracking](https://couriertrackingfinder.com/intelcom-express-tracking/)?Thanks for your time! Thankfully, my problem was fixed thanks to Steve above! Have a nice day my friend!
May 06 2022