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- c++ - Implementing memcmp - Stack Overflow
The code you found is just a debug implementation of memcmp, it's optimized for simplicity and readability, not for performance The intrinsic compiler implementation is platform specific and smart enough to generate processor instructions that compare dwords or qwords (depending on the target architecture) at once whenever possible
- c++ - If memcmp is equivalent to by-member equality comparisons, should . . .
C++20 Since C++20, this debate has become somewhat pointless, since you can explicitly default comparison operators See also cppreference: Default comparisons (C++20) If you are able to implement operator== in terms of std::memcmp, that also means you can implement it using = default;: bool operator==(vector, vector) = default;
- What is the difference between memcmp, strcmp and strncmp in C?
memcmp compares a number of bytes strcmp and the like compare strings You kind of cheat in your example because you know that both strings are 5 characters long (plus the null terminator)
- c - What exactly does memcmp return? - Stack Overflow
The exact return values of strcmp and memcmp are not specified They can return any negative value if the first argument is logographically less and any positive number if it's greater So, a return value of -1 , -10 , -42 all mean the same thing
- c++ - memcmp - is there a faster way to bitwise compare two buffers . . .
(memcmp wil probably end up using SSE too under those circumstances, but it will have to do some tests first to make sure - and you can save the cost of those tests) Otherwise - just use memcmp Share
- I dont know how to use memcmp in c++ - Stack Overflow
The syntax of memcmp is int memcmp ( const void * ptr1, const void * ptr2, size_t num ); It compares the first num bytes of the block of memory pointed by ptr1 to the first num bytes pointed by ptr2, returning zero if they all match or a value different from zero representing which is greater if they do not
- How to call memcmp() on two parts of byte[] (with offset)?
I want to compare parts of byte[] efficiently - so I understand memcmp() should be used I know I can using PInvoke to call memcmp() - Comparing two byte arrays in NET But, I want to compare only parts of the byte[] - using offset, and there is no memcmp() with offset since it uses pointers
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