Table of Contents
- 1 Can you memcpy a struct?
- 2 Can we use string in struct?
- 3 How do you assign one struct to another?
- 4 What can I use instead of memcpy?
- 5 How do you initialize a string in structure?
- 6 Why memcpy is used?
- 7 What is the difference between memcpy and struct1=struct2?
- 8 How to copy a block of memory from a location?
Can you memcpy a struct?
4 Answers. The struct1=struct2; notation is not only more concise, but also shorter and leaves more optimization opportunities to the compiler. The semantic meaning of = is an assignment, while memcpy just copies memory. That’s a huge difference in readability as well, although memcpy does the same in this case.
How do I add memcpy in C++?
The memcpy() function accepts the following parameters:
- dest – pointer to the memory location where the contents are copied to. It is of void* type.
- src – pointer to the memory location where the contents are copied from. It is of void* type.
- count – number of bytes to copy from src to dest . It is of size_t type.
Can we use string in struct?
The answer is yes unless you are using an obsolete compiler that does not support initialization of structures with string class members.
What is memcpy CPP?
memcpy() is used to copy a block of memory from a location to another. It is declared in string.h. // Copies “numBytes” bytes from address “from” to address “to” void * memcpy(void *to, const void *from, size_t numBytes); Below is a sample C program to show working of memcpy().
How do you assign one struct to another?
The simple solution is to use C++ and implement copy constructors and assignment operators for each structure or class, then each one becomes responsible for its own copy semantics, you can use assignment syntax, and it is more easily maintained.
Where is memcpy defined?
memcpy is declared in the standard header h> (or in C++). Its definition depends on the implementation, and you ordinarily shouldn’t need to care about that.
What can I use instead of memcpy?
memmove() is similar to memcpy() as it also copies data from a source to destination.
How does memcpy work in C?
In the C Programming Language, the memcpy function copies n characters from the object pointed to by s2 into the object pointed to by s1. It returns a pointer to the destination. The memcpy function may not work if the objects overlap.
How do you initialize a string in structure?
You can’t initialize any members in a struct declaration. You have to initialize the struct when you create an instance of the struct. struct my_struct { char* str; }; int main(int argc,char *argv[]) { struct my_struct foo = {“string literal”}; }
How do you take user input in structure?
- scanf(“\%d”, a); should be scanf(“\%d”, &a); – pzaenger.
- Use int *info; and use malloc : Node n; , n.info = malloc((sizeof int) * a); . – lurker.
- Use a flexible array member.
- That won’t work, the structure definition is created a the time of compilation, and you get the size as run-time.
Why memcpy is used?
The function memcpy() is used to copy a memory block from one location to another. One is source and another is destination pointed by the pointer.
Can you assign one struct to another in C++?
In C/C++, we can assign a struct (or class in C++ only) variable to another variable of same type. When we assign a struct variable to another, all members of the variable are copied to the other struct variable.
What is the difference between memcpy and struct1=struct2?
The struct1=struct2; notation is not only more concise, but also shorter and leaves more optimization opportunities to the compiler. The semantic meaning of = is an assignment, while memcpy just copies memory. That’s a huge difference in readability as well, although memcpy does the same in this case.
What is memcpy() function in C++?
memcpy () in C/C++. memcpy () is used to copy a block of memory from a location to another. It is declared in string.h. Below is a sample C program to show working of memcpy (). 2) memcpy () leads to problems when source and destination addresses overlap. memmove () is another library function that handles overlapping well.
How to copy a block of memory from a location?
memcpy() is used to copy a block of memory from a location to another. It is declared in string.h.
Why is there so much confusion about struct copying?
Basically, there are a lot of disagreements about the corner cases in that thread on what the struct copy would do. It’s pretty clear if all the members of a struct are simple values (int, double, etc.). The confusion comes in with what happens with arrays and pointers, and padding bytes.