std::memset
From cppreference.com
Defined in header
<cstring>
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void* memset( void* dest, int ch, std::size_t count );
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Converts the value ch
to unsigned char and copies it into each of the first count
characters of the object pointed to by dest
. If the object is not trivially-copyable (e.g., scalar, array, or a C-compatible struct), the behavior is undefined. If count
is greater than the size of the object pointed to by dest
, the behavior is undefined.
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[edit] Parameters
dest | - | pointer to the object to fill |
ch | - | fill byte |
count | - | number of bytes to fill |
[edit] Return value
dest
[edit] Notes
std::memset
may be optimized away (under the as-if rules) if the object modified by this function is not accessed again for the rest of its lifetime. For that reason, this function cannot be used to scrub memory (e.g. to fill an array that stored a password with zeroes).
[edit] Example
Run this code
#include <iostream> #include <cstring> int main() { int a[20]; std::memset(a, 0, sizeof a); for (int ai : a) std::cout << ai; }
Output:
00000000000000000000
[edit] See also
copies one buffer to another (function) |
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copies the given wide character to every position in a wide character array (function) |
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assigns a range of elements a certain value (function template) |
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assigns a value to a number of elements (function template) |
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(C++11)
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checks if a type is trivially copyable (class template) |
C documentation for memset
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